Chapter 3 Ch3
User Manual: Chapter 3 DL205 Counter Interface Manual
Open the PDF directly: View PDF 
.
Page Count: 26
| Download | |
| Open PDF In Browser | View PDF |
Mode 10 – High Speed UP Counters In This Chapter. . . . Ċ Wiring the UP Counter Mode Ċ Configuring the UP Counter Ċ Writing the Control Program Ċ Verification of Proper Operation Ċ Troubleshooting 13 3–2 High Speed UP Counter Using the UP Counters, Mode 10 It is recommended that you read Chapter 1, Getting Started, which introduces the six different modes of operation of the D2–CTRINT module, before selecting a mode. Even though several features can be mixed from several modes, one of the modes must be selected as the primary mode. Mode 10, High Speed UP Counter, will be the only mode covered in this chapter. It is also important to read Chapter 2, concerning the general guidelines for wiring a field device to the module. You also may want to refer to Chapter 2 as you learn about the D2-CTRINT’s high speed UP counting function. DL240/250–1/260 Applications Default Settings for DL240/250–1/260 UP Counter, Mode 10 Enable CW CCW Dummy D2–CTRINT Input Points D2 Reset Reset 00 Up count 1 Reset 02 Enable 01 Dummy 03 Reset Program signals Nj External signals Nj Up count 2 Reset Mode 10 UP Counter Installation and Safety Guidelines Reset Nj Program signals Nj External signals Note: Refer to pages 2–4 and 2–5 when wiring your particular device. The above diagram shows points 00 and 01 which are the primary UP counter connecting points for field devices while points 02 and 03 are the respective reset inputs. The two counters can be reset either through the operating program using relay ladder logic or they can be reset by an external field device connected to points 02 and 03. Point 04 is for a pulse output signal, but is not used in this mode. Refer to pages 2–4 and 2–5 when connecting your device. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–3 High Speed UP Counter DL230 Applications Unlike the DL240/250–1/260 CPU, the DL230 CPU has only one high speed counter embedded in its architecture. The diagram below shows the default settings for the UP Counter mode. Default Settings for DL230 UP Counter Mode 10 CW CCW Enable Dummy D2 D2–CTRINT Input Points 00 Not Used Reset Not Used Reset Nj Up count 1 Reset Program signals Nj External signals 01 02 03 Note: Refer to pages 2–4 and 2–5 when wiring your particular device. In this example, the first channel (point 00) receives the input from the device or equipment sending the DC level signals for counting. The third channel (point 02) is configured so that it can be wired to some device that will trigger an external reset. The other two points (points 01 and 03) are not used when the defaults are accepted. Refer to pages 2–4 and 2–5 when wiring your device to the D2–CTRINT module. Installation and Safety Guidelines DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–4 High Speed UP Counter Understanding V-Memory Setup Locations The D2-CTRINT needs to have the V-memory configured in order to use the UP Counter, Mode 10. V-memory location V7633 is the most important of all the reserved memory areas because it stores the numeric value which lets the CPU know which mode has been selected. The following diagram shows the 16-bit word and the various information it stores, including the values used for the D2–CTRINT. The example shown here is for a DL230 and uses the UP counting mode. The lower bits are set to 10 for the mode, and the upper bits are set to 10 so the battery backup is enabled. Together they form the number 1010. Bits 15 14 13 Memory Location V7633 12 11 10 9 8 7 6 5 0 0 0 1 Installation and Safety Guidelines Mode 10 UP Counter DL230 Example 0 1 0 0 0 0 0 0 0 1 4 3 2 1 1 0 0 0 0 0 0 Miscellaneous Setup Binary Coded Decimal: D2-CTRINT Mode Setup Binary Coded Decimal: 00 = Not Used (default) 10 = Battery Enabled (DL230/240/250–1/260) 20 = Power Up in Run (DL230 only) 30 = Selects both Battery Enable and Power Up in Run (DL230 only) 40 = Mode Change Enable in K–sequence (DL240 only) 50 = Battery Enable and Mode Change Enable in K–sequence (DL240 only) 00 = Not Used 10 = UP Counting Mode 20 = UP/DOWN Counting Mode 30 = Pulse Output Train 40 = High Speed Interrupts 50 = Pulse Catching 60 = Discrete Filtered Inputs NOTE: It is important to look at the entire 16 bits of V7633. For simplification, zeros have been placed in bits 8 thru 15 for all ladder logic examples when loading the mode codes. There are also other V-memory locations which contain High Speed Counter Interface setup information for each I/O point. The CPU will automatically configure them with default values for the mode which has been selected. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–5 High Speed UP Counter Default Settings for Counter Mode 10 CW Enable CCW Dummy D2 Reset DL230 Defaults Up count 1 Reset 00 Not Used Reset Not Used Nj 01 03 Dummy DL240/250–1/260 Defaults Note: Refer to pages 2–4 and 2–5 when wiring your particular device. Reset Nj External signals 02 Enable Reset Program signals Reset Nj 00 Up count 1 Reset 02 Enable 01 Dummy 03 Reset Nj External signals Nj Up count 2 Reset Program signals Program signals Nj External signals The above diagram shows the physical layout of the front of the module. The actual wire connecting points on the module can be visually related to the various functions that are associated through the default configuration. There are programming examples in this chapter which show how to change some of these defaults. Default settings with V7633 set to XX10: V–Memory Location and Default Value in Module I/O Points DL230 Default Value in DL240/250–1/260 0001 (Counter Input) 0001 (Counter 1 Input) V7635 (point 01) 0000 (Not Used) 0001 (Counter 2 Input) V7636 (point 02) 0007 (Reset Input) 0007 (Reset Input) V7637 (point 03) 0000 (Not Used) 0007 (Reset Input) The values shown above have the following meaning: 1 = absolute counting mode input 7= external reset input without an interrupt While discussing memory configuration, it is good to know about the reserved memory for the presets. Below is a table with the default memory locations. CPU Channel 1 (pt.00) Channel 2 (pt.01) DL230 V2320 thru V2377 Not Applicable DL240/250–1/260 V3630 thru V3707 V3710 thru V3767 DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines V7634 (point 00) 3–6 High Speed UP Counter Setting Up the CPU Configuring the V–Memory Installation and Safety Guidelines Mode 10 UP Counter Step 1: Entering the Selected Mode Each of the DL230, DL240, DL250–1 or DL260 CPUs will check V-memory to see if there is a High Speed Counter Interface Module present. The value XX10 will be read in V7633 if the module has been properly configured for UP counting. The XX represents the upper byte of V7633 value which handles such functions as enabling the backup battery and setting the PLC to start in the RUN mode. If the CPU finds that a D2–CTRINT module is present, it will check other V-memory locations to see how each point of the module has been configured. The values can be inserted into memory by using either a handheld programmer or a program edited with DirectSOFT32. There are program examples in this chapter for each counter function and mode. The following steps is a guide for configuring the V-memory for the UP counter function. The UP Counter is Mode 10 which is the value to be set into V7633. The following DirectSOFT32 diagram shows the setup procedures for communicating with your DL230, DL240, DL250–1 or DL260 CPU. Refer to DirectSOFT32 Programmers User Manual for more details. Setting the V-Memory using RLL Setting the V-Memory using the Memory Editor Editing the D2–CTRINT setup at the beginning of the user program is the most common method for setting up the counter mode. Should there be a need to change any of the counter setup values after the PLC has been put in the RUN Mode, use the Memory Editor to change the values. These values will only be temporary. They should be put into the program if they are to be permanently used. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–7 High Speed UP Counter The following RLL example shows how to set the D2–CTRINT to Mode 10, UP Counter, in V-memory location V7633. DirectSOFT32 Display SP0 LD K10 Load Mode 10 in Accumulator Note: The upper 4 bits are not used in this case. OUT V7633 Transfer Contents of Accumulator to V7633 Step 2: Select the Preset Mode (DL240/250– 1/260 Only) Two commands are needed to put the values into V-memory. The value must first be loaded into the accumulator of the CPU, then the CPU must transfer the value to the memory location. In this case, 10 is to be placed in V7633. This value is loaded into the accumulator, LD K10. The CPU then writes this data to the memory location, V7633, once it reads the OUT command, OUT V7633. Notice that an SP0 contact is used in this rung. This relay is on for the first scan only. This will load the values into memory initially, thereby keeping the scan time to a minimum. If a DL230 is being used or if the Absolute counting mode is accepted for a DL240, DL250–1 or a DL260, you can skip this step. The CPU automatically assumes that the absolute presets are being used and configures the V-memory accordingly. There is only one preset mode for the DL230––Absolute. There are two different preset modes for the DL240/250–1/260,––Absolute and Incremental. The Absolute preset mode can be selected for one counter and the Incremental preset mode can be selected for the second counter, or both counters can be configured to use the same preset mode. Installation and Safety Guidelines DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–8 High Speed UP Counter To understand the concepts of using the Absolute and Incremental preset modes, it is essential to know some basics about the counter’s presets. Inside the PLC’s memory are twenty–four (24) preset values which can be setup for each counter. A preset is the number of pulses which are set into V–memory to be counted before an event is to be initiated. Presets are entered into successive areas of V-memory. The presets are all independent in the Absolute mode. That is, the counter compares the actual total count received from the D2–CTRINT module to a preset, when the two are equal, the event is triggered. With an Incremental preset mode, however, the presets are related to each other. In such case, the counter reaches preset A and triggers event A, then preset B is added to preset A and that becomes the number of pulses which must be counted before event B is triggered. Preset C is added to the sum of presets A and B –– that is the number of pulses required for event C to be triggered. The process of adding all the presets continues until the CPU is notified that there are no more presets to satisfy. Below is an example showing the difference between using the presets incrementally and absolutely. Incremental F Event C Mode 10 UP Counter Preset=150 F (A +B) Event B Preset=100 Event A Preset=50 Pulse Count Installation and Safety Guidelines (A +B+C) F = Trigger point Absolute F Event C Preset=150 F Event B Preset=100 F Event A Preset=50 100 200 300 400 F 100 200 300 400 Assume that a limit switch (SW1) is being connected to one of the high speed counters. The counter is to initiate three different events at certain points in time determined by the pulse count received. Also, assume that the presets are stored (associated with each of the three events) in successive memory as 50, 100, and 150. In this example, these values are to be attended to in an incremental fashion. The counter would, in such case, trigger the 1st event when it counts 50 pulses, the 2nd event when it receives 150 pulses total (50 + 100 ) and the 3rd event when it receives 300 pulses total ( 50 + 100 + 150 ). The result would have been different if the counter had been configured to count in the Absolute mode. In such case, the counter would trigger the 1st event when it counted 50 pulses, the 2nd event when it received 100 pulses and the 3rd event when it counted 150 pulses. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–9 High Speed UP Counter Configuring the Preset Mode Select the Preset mode to be used by placing the proper value in memory location V7634 and/or V7635. If only one of the counters for a DL240, DL250–1 or DL260 is being used, place a counter preset value in one of these locations. The value for Absolute is 0001 and the value for Incremental is 0101. V7634 holds the value for Channel 1 (point 00), and V7635 holds the value for Channel 2 (point 01). The DL230 does not require either of these choices; because there is only one counter which is absolute. In this example, all the upper bits of V7633 are set to the default value of all zeros. DirectSOFT32 Display SP0 LD K10 Mode 10 UP Counter OUT V7633 LD K1 Point 00 Absolute Preset OUT V7634 LD K101 Point 01 Incremental Preset OUT V7635 The previous RLL example which set the D2–CTRINT to Mode 10 now has the two preset values added to it. The CPU is set for the counter to use the Absolute preset mode at point 00 and to use the Incremental preset mode at point 01. Step 3: Using Presets The following RLL diagram loads presets into consecutive V-memory locations, starting with the default memory location V3630. Use LDD and OUTD instructions as indicated in the example below: DirectSOFT32 Display SP0 . LDD K100 OUTD V3630 First preset for first counter Preset=100 LDD K4000 OUTD V3632 LDD K7500 OUTD V3634 LDD K12000 OUTD V3636 Second preset for first counter Preset=4000 Third preset for first counter Preset=7500 Fourth preset for first counter Preset=12000 DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines The final step for setting up the CPU is to configure the presets. There are up to 24 presets per counter available, also internal equal relays are embedded in the CPU so that you can use the presets for triggering events inside the RLL program. 3–10 High Speed UP Counter Triggering Presets to Outside Events Each of the presets are associated with special relays called equal relays. Each equal relay is assigned its corresponding preset value into two 16-bit V-memory addresses. Below is an example of how to use the equal relays. They can be referenced in relay ladder logic like a standard RLL relay. Outside events are triggered whenever the preset assigned to a particular relay is satisfied by the pulse count, the relay closes. DirectSOFT32 Display SP570 Mode 10 UP Counter Installation and Safety Guidelines DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Preset #2 met. SP571 Preset #3 met. SP572 Preset #4 met. SP573 . Preset #1 met. Y10 OUT Y11 OUT C14 OUT Y13 OUT Equal relays used to trigger outside events. Can be used in main program or in subroutines. 3–11 High Speed UP Counter DL240/250–1/260 Equal Relays DL230 Equal Relays Channel 2 (point 01) Channel 1 (point 00) SP540 (V3631/V3630) SP570 (V3711/V3710) SP540 (V2321/V2320) SP541 (V3633/V3632) SP571 (V3713/V3712) SP541 (V2323/V2322) SP542 (V3635/V3634) SP572 (V3715/V3714) SP542 (V2325/V2324) SP543 (V3637/V3636) SP573 (V3717/V3716) SP543 (V2327/V2326) SP544 (V3641/V3640) SP574 (V3721/V3720) SP544 (V2331/V2330) SP545 (V3643/V3642) SP575 (V3723/V3722) SP545 (V2333/V2332) SP546 (V3645/V3644) SP576 (V3725/V3724) SP546 (V2335/V2334) SP547 (V3647/V3646) SP577 (V3727/V3726) SP547 (V2337/V2336) SP550 (V3651/V3650) SP600 (V3731/V3730) SP550 (V2341/V2340) SP551 (V3653/V3652) SP601 (V3733/V3732) SP551 (V2343/V2342) SP552 (V3655/V3654) SP602 (V3735/V3734) SP552 (V2345/V2344) SP553 (V3657/V3656) SP603 (V3737/V3736) SP553 (V2347/V2346) SP554 (V3661/V3660) SP604 (V3741/V3740) SP554 (V2351/V2350) SP555 (V3663/V3662) SP605 (V3743/V3742) SP555 (V2353/V2352) SP556 (V3665/V3664) SP606 (V3745/V3744) SP556 (V2355/V2354) SP557 (V3667/V3666) SP607 (V3747/V3746) SP557 (V2357/V2356) SP560 (V3671/V3670) SP610 (V3751/V3750) SP560 (V2361/V2360) SP561 (V3673/V3672) SP611 (V3753/V3752) SP561 (V2363/V2362) SP562 (V3675/V3674) SP612 (V3755/V3754) SP562 (V2365/V2364) SP563 (V3677/V3676) SP613 (V3757/V3756) SP563 (V2367/V2366) SP564 (V3701/V3700) SP614 (V3761/V3760) SP564 (V2371/V2370) SP565 (V3703/V3702) SP615 (V3763//V3762) SP565 (V2373/V2372) SP566 (V3705/V3704) SP616 (V3765/V3764) SP566 (V2375/V2374) SP567 (V3707/V3706) SP617 (V3767/V3766) SP567 (V2377/V2376) NOTE: The consecutive addresses shown above for each relay are those assigned by the CPU as default addresses. Pointers for the start of these addresses are stored by the CPU at V7630 and V7631 for the DL240/250–1/260 and V7630 for the DL230 only. If there is a conflict of addresses because of pre-existing code written to these addresses, change the default block of addresses by placing a different pointer value in V7630 or V7631 in the relay ladder logic, depending on the CPU and preference. For example, to change the starting address for the relays belonging to Channel 1 to V2500, change the program to write an octal 2500 to V7630. The results are that the CPU will reserve 48 consecutive 16-bit memory addresses (32 bits per preset for the 24 presets available) for SP540 to SP567 equal relays. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines Channel 1 (point 00) 3–12 High Speed UP Counter Custom Configurations There may be a time when the factory defaults will not satisfy an application. In this case the defaults can be changed so the D2–CTRINT can work for almost any application. The following tables are provided with the values needed for custom configurations. DL230 Custom Configuration Mode 10 Options for the DL230 Point Number V-Memory Definition Location Hex Value point 00 V7634 UP Counter #1 (default) 0001 (absolute) default point 01 V7635 Not Used (default) 0000 default Discrete Input xx06 * Reset UP Counter (default) 0007 (no interrupt) default point 02 V7636 0107 (interrupt) Mode 10 UP Counter point 03 point 04 V7637 Not Used Discrete Input xx06 * Not Used (default) 0000 default Discrete Input xx06 * Pulse Output (CCW) Not Used Note: The lower byte of V7633 is set to 10. * xx = filter time. Filter time range = 0 to 99ms. Installation and Safety Guidelines For the filtered inputs, the xx signifies the filter time in milliseconds, i.e. 1006 is a 10ms filter. For the DL230, either place zeros (0) in V7635, V7636 and V7637 or enter the proper hex value for the discrete input point. The DL240/250–1/260 has more options to chose for custom configuring. The chart on the next page shows you those options. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–13 High Speed UP Counter DL240/250–1/260 Custom Configuration Point Number point 00 V-Memory Location V7634 Definition Hex Value UP Counter #1 0001 (absolute) default 0101 (incremental) point 01 V7635 UP Counter #2 0001 (absolute) default 0101 (incremental) point 02 V7636 Pulse Catcher 0005 Discrete Input xx06 * Reset UP Counter #1 0007** (no interrupt) default no Z pulse or index marker recognition 0107 (interrupt) can recognize Z pulse or index marker 0207 (interrupt) no Z pulse or index marker recognition 0307 uses Z pulse recognition in the interrupt point 03 V7637 Pulse Catch 0005 Discrete Input xx06 * Reset UP Counter #2 0007** (no interrupt) default no Z pulse or index marker recognition 0107 (interrupt) can recognize Z pulse or index marker 0207 (interrupt) no Z pulse or index marker recognition point 04 (Mode 30) Not Used Pulse Catch 0005 Discrete Input xx06 * Pulse Output (CCW) Not Used Note: The lower byte of V7633 is set to 10. * xx = filter time. Filter time range = 0 to 99ms. ** In a high speed application using a high resolution encoder, with the CPU programmed with presets that span the resolution of the encoder, you may lose pulses in the higher range of presets. When using constants K7 or K107 in V7636 or V7637, the counter module will read the preset V–memory each time the counter is reset or at the index marker location. When using K207 or K307, the counter module reads the preset V–memory only at power up, or when a CPU mode change occurs (i.e. PROGRAM to RUN transition). NOTE: If presets are written to V-memory for the D2–CTRINT module during program execution the counter may not be able to run at high speed, high resolution applications, since reading these locations during a reset may result in lost pulses. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines 0307 uses Z pulse recognition in the interrupt 3–14 High Speed UP Counter Writing the Control Program The control program is ready to be written after the High Speed UP Counter parameters have been configured. Writing the RLL program for the High Speed Counter is much the same as for a regular counter. The embedded high speed counters which are activated through the D2–CTRINT module, have three inputs. The first input is to enable the counter, the second one is a dummy and the third is to reset the counter. The dummy has no function other than it is required by DirectSOFT32. The three inputs are required for DirectSOFT32 to accept the program. DirectSOFT32 Required ENI Enable Input Dummy Input UDC CT76 K17688 Mode 10 UP Counter Reset Input Installation and Safety Guidelines Must be: CT76 for a DL230 CT174 for point 01 or CT176 for point 02 for the DL240/250-1/260 Preset Range: 1-99,999,999 The mnemonic for the counter is UDC. It is found in the DirectSOFT32 instruction browser that pulls down using the F7 hotkey while in the Edit Mode. After selecting the UDC, a box appears asking for the counter address and preset value. The counter address in the above example is CT76. This is the address which must be used for the DL230 CPU. The preset value of 17688 has been used in the example. This is the number of pulses to be received and counted before the output of the counter goes high. Any value between 1 and 99,999,999 can be programmed. The DL240/250–1/260 CPUs require addresses of CT174 for Channel 1 (point 00) and CT176 for Channel 2 (point 01). If a different address is used, the CPU will think that a standard, non-high speed, counter has been programmed, and the D2–CTRINT will not be enabled. After entering the counter address and preset, enter the contact addresses for the contacts which are automatically drawn in the RLL program. High Speed Counter data CPU Counter No. for Channel 1 (pt 00) Counter No. for Channel 2 (pt 01) Preset Limits DL230 76 N/A 1–99,999,999 DL240/250–1/260 174 176 1–99,999,999 DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–15 High Speed UP Counter Example 1: UP Counters Without Presets The following example uses either a DL240, a DL250–1 or a DL260 CPU. The example also uses both UP counters at points 00 and 01, and the resets at points 02 and 03. The counter attached to point 00 is to trigger a jump to an interrupt subroutine when it is externally reset by point 02. There is no interrupt subroutine written for the reset for point 03. The second counter resets after receiving 20,456 pulses. SP0 ENI Enables Interrupts SP0 LD K0010 DirectSOFT32 Display OUT V7633 Select UP Counter Mode 10 LD K1 OUT V7634 Absolute mode (point 00) OUT V7635 Absolute mode (point 01) LD K107 OUT V7636 External Reset w/Interrupt (point 02) (Custom) LD K7 OUT V7637 SP1 SP1 External Reset wo/Interrupt (point 03) (Default) UDC CT174 K18724 SP1 First Counter for point 00 (External Reset at point 02) SP1 SP1 UDC CT176 Second Counter for point 01 (Self-Resetting or External Reset at Point 03.) END Interrupt Subroutine INT O0 C6 C7 X2 Y10 OUT Y11 OUT Y20–Y27 RSTI IRT The outputs in this subroutine illustrate that the events do not have to be tied to the equal relays. When the external reset at point 02 (X2) for Counter #1 goes high, the counter is reset to zero(0) and Y20 through Y27 are reset immediately. Notice the counters have been properly labeled CT174 and CT176. The presets have been set to the respective numbers specified. The load accumulator instructions have setup the V-memory as required, i.e. 10 in V7633 for the mode, 1 in V7634 and V7635 for absolute mode and 0107 in V7636 to trigger a jump to an interrupt subroutine. Also in the setup is the reset of the counter CT174 when point 02 goes high and 0007 in V7637 to indicate no jump to an interrupt subroutine when CT176 is externally reset. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines K20456 CT176 3–16 Mode 10 UP Counter High Speed UP Counter Reset with an Interrupt In the previous example, whenever point 02 is enabled, CT174 is reset to zero (0). At the same time, the CPU suspends its normal main program scan and execution, going to the interrupt subroutine. When it finishes executing the subroutine and encounters the return statement, the execution returns to the exact point in the main program where it left off. Notice the interrupt subroutine must be labeled to match the input point to which its corresponding counter is wired, i.e. 00 is used. Interrupt Operation in Ladder Logic The programmer should be aware of the sequence of events during an interrupt in order to avoid unexpected I/O operations. When an interrupt occurs, the CPU halts execution of the current instruction. It then executes the interrupt program, then returns to complete the suspended instruction. If the suspended instruction involves the same memory byte as an operation in the interrupt program, the CPU may not retain the correct status of that byte. This is because I/O status is updated one byte at a time. EXAMPLE: An interrupt occurs during execution of the “OUT Y17” instructin, which has read the current status of the I/O byte which contains Y17. The interrupt program in this example sets Y10, a bit which is in the same byte as Y17. When control returns to the suspended instruction, it uses the status it read from the I/O status table before the interrupt to complete its operation. It turns Y17 ON, but still has the old value for Y10 (OFF). When the byte is written to the I/O status table, the CPU has lost the result of the interrupt operation. To avoid this problem, the programmer should use control relays (C memory) in bytes unused elsewhere for SET or OUT operations in the interrupt programs. I/O Status 17 Y10 0 0 0 0 0 0 0 0 Main Program Interrupt Program Execution of OUT Y17 Installation and Safety Guidelines Installation and Safety Guidelines Status Read 0 0 0 0 0 0 0 0 Store 8 bit status data INT0 occurs Interrupt Program for INT0 17 Y10 0 0 0 0 0 0 0 0 Status Read Execution of SET Y10 0 0 0 0 0 0 0 0 17 Y10 0 0 0 0 0 0 0 1 Y10 turns ON Status Overwrite Continues Execution of OUT Y17 Status Overwrite 1 0 0 0 0 0 0 0 17 Y10 1 0 0 0 0 0 0 0 Y10 turns OFF DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Bit 7 turns on 0 0 0 0 0 0 0 1 3–17 High Speed UP Counter Example 2: UP Counters with Multiple Presets The next DL240/250–1/260 example will use some features from other modes with multiple presets for a single counter. The example will use only one counter for point 00 configuring the preset mode as absolute and having a reset with an interrupt at point 02. Point 01 will be made a pulse catcher and point 03 will be used as a discrete filtered input. Referring to page 3–13 the V–memory locations for control points 01 and 03 are V7635 and V7637 respectively. This is true for any mode or mix that is used. Place 0005 in V7635 for the pulse catch input, and xx06 in V7637 for the filtered discrete input. This example will use 10 ms for the filtered time constant. The value to put in V7637 is 1006. The relay ladder logic to accomplish this is on the next page. This example also uses multiple presets of 5000, 10000 and 15000 for the counter. Memory Locations for Multiple Presets Counter No. Memory Range/Default Preset Addresses Equal Relays 76 (DL230) V2320 to V2377 SP540–SP567 174 (DL240/250–1/260) V3630 to V3707 SP540–SP567 176 (DL240/250–1/260) V3710 to V3767 SP570–SP617 NOTE: The above table indicates the default V-memory locations for setting the presets and the corresponding special equal relays assigned to each. Be aware that the default addresses can be changed to begin elsewhere merely by changing the pointers at V7630 (Channel 1) and V7631 (Channel 2) to the octal value of the new addresses. NOTE: When using two counters with the SP570 contacts,etc., INT01 must be used. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines Each preset requires two V-memory locations (32–bits), i.e. V2320 and V2321 are the first preset, V2322 and V2323 are the second, etc. Each of these presets has a special equal relay assigned to it. The numbering assignment for these are one digit apart, i.e. SP540 assigned to the first preset, SP541 assigned to the second preset, etc. So that the CPU knows that it has seen all the presets when in the Absolute mode, place an FFFF in the next available V-memory preset location following the final preset (if not using all 24 presets available). In the Incremental mode, place FFFF as in the Absolute mode or place FF00 in the last preset location to reset the counter, set the accumulated pulse count to zero (0) and continue counting. In the example, this has been placed in V3636 since the last preset was in V3634 and only using three presets. Place 00FF in the last preset location to reset the counter and not reset the accumulated pulse count. 3–18 High Speed UP Counter DirectSOFT32 Display SP0 DL240/250–1/ 260 Example SP0 ENI LD Enables Interrupt, to use Special Relays K10 OUT V7633 Mode 10 LD K1 OUT V7634 Absolute mode at point 00 LD K5 OUT V7635 LD K107 OUT V7636 LD K1006 OUT V7637 Pulse Catcher at point 01 External Reset w/Interrupt (point 02––X2) Discrete 10 ms Filtered Input (point 03) LDD K5000 Mode 10 UP Counter OUTD V3630 LDD K10000 OUTD V3632 Additional Presets for Counter of 5000, 10000 and 15000 LDD K15000 OUTD V3634 Installation and Safety Guidelines LDD KFFFF OUTD V3636 Tell CPU that there are no more presets. SP1 SP1 UDC CT174 K18724 Counter for point 00 SP1 END INT O0 SP540 SP541 SP542 X2 Y20 SET I Y21 SET I Y22 SET I Y20–Y27 RSTI IRT Interrupt Subroutine Subroutine will be executed when the Preset equals the Current Count and the Reset is triggered. NOTE: To trigger outside events with the three presets, assign SP540,541 and 542 respectively to V3630, V3632, and V3634. (See Table on Page 3-11. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–19 High Speed UP Counter Example 3: Speed Control for an AC Motor The next example will use one UP counter for a DL240, DL250–1 or DL260 to control the timing for a small AC motor inverter. Unlike the positioning applications discussed later in Chapter 5 for the pulse train function (Mode 30) where the interface module does all the ramping and speed control of a stepper motor, this application will rely on a separate motor drive to provide all of the intelligence for proper acceleration/deceleration ramping and motor speed control for an AC induction type motor. Velocity High Medium Low 100 Pulse Count (Time) 4000 10000 17000 Y10 Y11 Y12 Assume that there are input and output modules in a DL205 base and that X10 and X11 of the input module are wired to a START/STOP switch. The inverter being used in this example has programmable input relays that accept low, medium and high speed ranges that have been programmed into the drive. The drive automatically powers up at the low speed setting. Low, medium and high speed input relays are wired to Y10, Y11 and Y12 respectively. The goal here is to write the appropriate relay logic to accomplish the above start and stop of the drive to match the curve shown above. Input Output D2ĆCTRINT Module Module 00 X10 X11 Y10 Y11 Y12 3-Speed Drive Low Medium High AC Motor Start Stop Encoder DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines Speeds 3–20 High Speed UP Counter Example Program DirectSOFT32 Display SP0 ENI SP0 LD K10 OUT V7633 Select UP Counter Mode 10 LD K1 OUT V7634 Absolute mode at point 00 LDD K100 OUTD V3630 LDD K4000 OUTD V3632 LDD K10000 Presets of 100, 4000, 10000, and 17000. Mode 10 UP Counter OUTD V3634 LDD K17000 OUTD V3636 LDD KFFFF Installation and Safety Guidelines OUTD V3640 Tell CPU there are no more presets. SP1 SP1 UDC CT174 Counter for point 00 K20000 X11 X10 C10 X11 C10 PD Y10 SET Y10–Y12 RST END INT O0 SP540 SP541 SP542 SP543 Y11 SET I Y12 SET I Y12 RST I Y10 Y11 RST I IRT DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 100 pulses 4000 pulses 10000 pulses 17000 pulses Interrupt Subroutine 3–21 High Speed UP Counter Explanation of RLL The following describes the events as they are scanned and executed in the example program on the preceding page. 1. The START button, which is connected to X10, is pressed. Y10 latches ON and the inverter starts ramping to low speed. 2. When the D2-CTRINT counts 100 pulses, which is the first preset (100), SP540 goes HIGH and latches Y11 ON. This switches the inverter to medium speed mode. 3. When the D2-CTRINT counts 4000 pulses, the second preset, SP541 goes HIGH and latches Y12 ON. This switches the inverter to the high speed mode. 4. When the D2-CTRINT counts 10000, SP542 goes HIGH and unlatches (resets) Y12 OFF. This switches the inverter back into the medium speed mode. 5. When 17000 pulses are counted, the fourth preset, SP543 goes HIGH and resets outputs (Y10, Y11) OFF. This turns the inverter OFF. Installation and Safety Guidelines DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–22 High Speed UP Counter Example 4: Counting Pulses at a High Frequency Where Accuracy is Critical In this example, wire being drawn from a spool is constantly being labeled and cut to length. The process requires continuous unwinding of the wire for cutting. An encoder is connected to a roller shaft and is producing pulses at a high frequency which are used to determine the length of the wire for cutting. A reset of the counter at these high frequencies would cause a loss of pulses (depending on CPU scan time) and result in some wire lengths to be inaccurate. To avoid this problem, a program can be written that resets the counter immediately at the proper preset (to be determined) with no loss of pulses. DirectSOFT32 Display SP0 ENI SP0 Enables Use of Interrupts LD K10 OUT V7633 Mode 10 LD K101 Mode 10 UP Counter OUT V7634 LD K101 OUT V7635 Incremental preset mode at point 00 (first counter) Incremental preset mode at point 01 (second counter) LD K7 OUT V7636 External reset without interrupt for first counter. LD K7 Installation and Safety Guidelines OUT V7637 SP0 LDD K1 External reset without interrupt for second counter. First preset for first counter OUTD V3630 LDD K499 OUTD V3632 LDD K7500 Second preset for first counter Third preset for first counter OUTD V3634 LDD K12000 Fourth preset for first counter OUTD V3636 LDD KFF00 OUTD V3640 Continued on next page DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Reset the first counter 3–23 High Speed UP Counter DirectSOFT32 Display SP1 SP1 UDC CT174 First Counter K99999 SP1 Second Counter not being used. END INT O0 SP540 SP541 Interrupt Subroutine Wire Cutter Y20 SET I Wire Cutter Y20 RSTI Gauge Labeler Y21 SET I External Counter Y23 SETI SP542 Turn Off the Wire Cutter Turn On Gauge Labeler Increment External Counter (User Supplied) Turn Off Gauge Labeler Part No. Labeler Y22 SET I Turn On Part No. Labeler Part No. Labeler Y22 RST I Turn Off Part No. Labeler External Counter Y23 RSTI IRT Increment External Counter Return from Interrupt Subroutine to main program Equal Relays SP540, SP541, SP542 and SP543 turn ON when their respective presets are reached. They are Incremental and not Absolute; each preset is added to the previous preset. For example SP542 goes ON when (1+499+7500) or 8000 total pulses have been reached. Note the use of SETI and RSTI instructions inside the interrupt routine. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines SP543 Gauge Labeler Y21 RSTI Turn On Wire Cutter and Cut 3–24 High Speed UP Counter Troubleshooting Installation and Safety Guidelines Mode 10 UP Counter Things to check Counter Doesn’t Count No Input Signal The following information may provide some assistance in dealing with problems which may be encountered when setting up the D2–CTRINT module, should they occur. Experience has shown that most problems occur because of improper configuration. Always re-check the CPU setup before anything else. For verifying types of inputs (or outputs) besides those related to UP counting, see the Chapters in this manual covering the specific function. Listed below are some things that could possibly go wrong with the UP counter inputs: 1. The UP counter is not counting when the encoder or other device is making low to high transitions. 2. The status indicator LED is not lighting for the input point where the UP counter is wired (i.e. points 00 and 01). 3. The counter does not appear to be counting synchronously with the input device’s transitional states. 4. The counter is not resetting itself after reaching the preset. 5. The counter is not jumping to the subroutine as expected when the preset is reached. 6. The counter is counting properly and executing the interrupt properly, but it does not continue counting after the interrupt subroutine has been completed. The actual count should be in view when monitoring the counter with DirectSOFT32. If this is not happening: 1. The software configuration may be incorrect. Re-check the setup. 2. The field device may be defective. 3. The field device may be O.K., but it is too fast for the counter. 4. The wiring may be defective. 5. The input voltage may not be within specification. 6. The D2–CTRINT module is defective. Verify that there is a signal present at point 01 or 02. Check the encoder, or input device, which is connected to the module. Instrumentation can be used to check the outputs; either an oscilloscope or a logic test probe. If the logic test probe is used, it should be the type that has the option to select either TTL or CMOS settings, it should also be able to switch it to the pulse train mode. The peak signal level being output from points 03 and 04 is 5-volts with 15% tolerance. If the signals cannot be read with the TTL setting, use the CMOS setting. The probe may not be able to read the TTL because of the 15% tolerance specification. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A 3–25 High Speed UP Counter Touch probe to counter input points 01 and 02. Field device must be wired so that pulses are being sent. Typical Low Cost Logic Probe (Not available from AutomationDirect) High Signal Indicator Low Signal Indicator Pulse Train Indicator Normal/Pulse Train Switch TTL/CMOS Switch Connect power leads to your recommended power supply––not PLC power supply. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A Installation and Safety Guidelines A rotary encoder may also not be operating properly because of a poor coupling between the encoder and the motor shaft. Check to be certain that the coupling is not defective. Check the specifications of the field device. Make sure that the output signal matches up the specifications of the D2–CTRINT module. Too fast – The pulse rate cannot exceed 5 kHz. If this is suspect, try to slow down the pulse rate to see if the problem is solved. The pulse width may also be too narrow. The pulse must remain high for at least 100ms in order for the module to detect it. Wiring - Simple as this might seem, quite often poor wiring is the cause of many problems. Make sure that there is a complete electrical loop between the device and the input module. Along with visual inspection, use a voltmeter to check this. Input Voltage - If the input device is producing a signal which is less than 12 volts, the counter will either not function properly or function improperly. Use a field device with the proper signal level if necessary. Improper Configuration - The module may be looking for a counter which doesn’t exist. Check the RLL program and be sure that the counter is addressed properly. Be certain that the inputs to the counter are properly configured. Is the counter enabled? If using a DL230, only one High Speed Counter can be used. 3–26 High Speed UP Counter LED’s Do Not Light Make sure the PWR or BAT LED’s are not lit on the CPU module. If either the battery power or the external power indicators are not illuminated, there is either a defective power supply, the batteries are worn out or there is no power to the PLC. Check and be sure that the status indicators are blinking as pulse signals are received at the proper input point on the module (i.e. 0 or 1). Check the field device to make sure it is operating. Use an oscilloscope or digital counter to verify the presence of a pulse train at the input point(s) or use the Change Value feature in DirectSOFT32 to force the input point ON. Refer to the DirectSOFT32 Software Programmers Manual to use this feature. If after forcing the signal ON, and the appropriate LED does not light, the module is defective. Non–Synchronous If the counter is suspect of counting faster than the field device is sending pulses, then the interface may be experiencing noise. Try connecting a shielded wire Pulsing between the field device and the module input. The wire should be shielded at one end only-- normally the encoder side. If the PLC is interfaced to a rotary shaft encoder, a loose coupling could also be causing the problem. Check the coupling. If a reset is not present when expected, check the configuration. Is the proper value No Reset for a reset being used? Is the module looking for an external reset? If so, is the field device supplying the reset signal (which should be connected to either points 02 or 03) operating properly. Manually operate the reset device. Not Jumping to Is the interrupt subroutine labeled properly? The interrupt subroutine must have the same number as the I/O point to which the counter is connected. Is there supposed Interrupt to be an external interrupt, but the external device is not sending the signal? Does the external interrupt device meet the input criteria? Check all of these possibilities. Not Returning from Does the interrupt subroutine end with an Interrupt Return instruction in the RLL program? Is there an endless loop inside the subroutine? Is there a conditional Interrupt return and the condition has not been met? Installation and Safety Guidelines Mode 10 UP Counter WARNING: Take all necessary precautions to protect personnel and equipment when forcing inputs and outputs, since the equipment on the output side of the system may be energized. DL205 High Speed Counter Interface Manual, 2nd Ed, Rev. A
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.3 Linearized : Yes Create Date : 2003:03:24 15:48:38-05:00 Modify Date : 2003:03:24 15:48:38-05:00 Page Count : 26 Creation Date : 2003:03:24 20:48:38Z Mod Date : 2003:03:24 20:48:38Z Producer : Acrobat Distiller 5.0 (Windows) Author : ghawkinson Metadata Date : 2003:03:24 20:48:38Z Creator : ghawkinson Title : Document:EXIF Metadata provided by EXIF.tools