Electronic Systems Technology ESTEEM192S Wireless Modem User Manual part 2

Electronic Systems Technology Wireless Modem part 2

user manual part 2

CHAPTER 2MODES OF OPERATIONCOMMAND MODECONVERSE MODETRANSPARENT MODESEMI-TRANSPARENT MODEHARDWARE MODE CONTROL
CHAPTER 2MODES OF OPERATIONRevised: 11 Feb 99 2-2The ESTeem has three major modes of operation,Command, Converse, and Transparent. This chapter of themanual describes each one of these modes.COMMAND MODEThe COMMAND Mode (CMD: prompt) is the defaultmode that the ESTeem initially enters on power-up or aftera hardware or software reset. From this mode the user cancommand or program the ESTeem. In this mode the usermay access the various program commands to configure theESTeem for the specific application. These values can bestored in nonvolatile memory within the ESTeem by the useof the SAVE command. The ESTeem reads these setupparameters stored in memory on power-up or RESET. When programming in the COMMAND Mode, the userneed only enter enough characters to uniquely identify therespective command.Example: CMD:ADD 15 <cr>This enters the source address of the ESTeem to the decimalvalue of 15. The first three letters ADD were enough forthe ESTeem to uniquely identify the command forADDress. The number of characters that need to be typedvaries depending upon the command being entered. Insome cases, four or even more letters may have to beentered in order for the identification to be uniquelydetermined. Up to ten multiple commands can be writtenon the same line if separated by a colon.Example: CMD:ADD 15:SETC 2:SAVE <cr>CONVERSE MODEThis mode allows bi-directional communication from theinput/output device attached to the ESTeem to a destinationESTeem and its respective input/output device. TheESTeem will automatically switch to the CONVERSEMode after the initial CONNECT has been made.When the ESTeem is in the CONVERSE Mode the *prompt will be displayed. The ESTeem will remain in theCONVERSE Mode until the radio link has been broken orby typing a control character defined by the user with theCOMMAND variable.The factory default for the COMMAND variable is CTRLC. You can return to the CONVERSE Mode from theCOMMAND Mode by typing CONV <cr>.When you are in the CONVERSE Mode the echoing of thecharacter comes from the ESTeem if ECHO = ON (factorydefault) has been programmed in the ESTeem.Transmitting DataThe ESTeem will transmit data from the CONVERSEMode if one or more of the following conditions have beenmet.1. The ESTeem transmit buffer has been filled. The sizeof the transmit buffer is defined in the ESTeem by thePACKLEN variable. This variable is programmablefrom 1 to 2000 bytes. Factory default is 2000.2. The ESTeem receives a SENDPAC (send packet)character from the RS-232C input data stream. TheSENDPAC variable can be defined from 0 to 255 bythe user. Factory default is 13 (carriage return). TheSENDPAC character is also transmitted by theESTeem. In file dump applications the SENDPACcharacter can be programmed to be the EOF (end offile) character transmitted from the sending device (i.e.;CTRL Z, CTRL G, etc.).3. Termination control timer. The termination controltimer is enabled by the TERMC (on/off) command. When enabled, the termination timer starts from thetime the last transmit buffer has been updated in theRS-232C port. If the termination timer expires beforeanother character is received or transmitted, thecontents of the ESTeem transmit buffer will betransmitted. The waiting time of the timer is defined bythe TERMT variable (termination time). Theprogramming range of the TERMT variable is10-255ms. Factory default values are TERMC = OFFand TERMT = 50. It is noted that when thetermination timer is used, the SENDPAC variable isusually programmed to be a character that is nonoccurring in your data stream (i.e.; SENDPAC = 255)so that premature transmission does not occur.TRANSPARENT MODEThe TRANSPARENT Mode allows the ESTeem to pass alldata characters (O-255 or 0-FF hex) using 8 data bits.
CHAPTER 2MODES OF OPERATIONRevised: 11 Feb 99 2-3To program the ESTeem in the TRANSPARENT mode theTRANSPARent command must be enabled and switch Bit 8to ON (RS-232C Setup Switch). The TRANSPARentcommand will defeat the SENDPAC and COMMANDvariables and put the ESTeem in the transparent mode whenBit 8 is ON. The transmission of the data packets can only beaccomplished by enabling the termination controlcommands (TERMC and TERMT) or the PACKLENbuffer being filled. The value of TERMT should be slightlylonger than the maximum delay encountered duringRS-232C transmission. If this time is set to short, theESTeem will truncate your data stream improperly.When using the TRANSPARENT Mode, data flow controlis by hardware handshaking only. Hardware handshaking isinitiated by enabling hardware flow control (XHF = ON).The SETCON (Set Connect command) must be used todefine the node that you want to communicate with while inthe TRANSPARENT Mode. When the TRANSPARENTMode is enabled you can not communicate to the ESTeemin the COMMAND Mode unless you use the HardwareMode Control line (see explanation this chapter).To remove the ESTeem from the TRANSPARENT Modethe user must perform the following:1. Switch Bit 8, Off on the RS-232C Setup Switch.2. Reset the ESTeem from the front panel switch.3. Type Tra OFF <cr>. SEMI-TRANSPARENT MODEThis mode should be utilized when sending a non-ASCIIfile and there is a possibility that the SENDPAC charactercould be contained in the transmitted data set. Perform thefollowing prior to programming the ESTeem to initialize theunit to factory default settings:1. Turn Bit 8, OFF on the RS-232C Setup Switch.2. Reset the ESTeem.3. TYPE FA <cr>. Please note the characters may or maynot be echoed by the CRT. ESTeem-------------------------ADD xxx xxx = your addressSETC yyy yyy = destination addressTERMC ONTERMT 10SENDP 255EDIT OFFSAVEIf EDIT is off, and SENDPAC = 255, the SENDPACcharacter is disabled. This character when received will notcause packet transmission and will be passed as normaldata. The TERMC and TERMT commands are used totransmit the contents of the ESTeem transmit buffer.Software flow control in this example is still enabled(factory default XSF = ON) therefore the ESTeem will passall characters except the data flow control characters forXon/Xoff.HARDWARE MODE CONTROLThe MODECON (Mode Control) command is provided inthe ESTeem to change the mode of the ESTeem modemfrom COMMAND Mode to CONVERSE (orTRANSPARENT Mode) via a hardware control line. Thehardware line is located on pin 19 of the RS-232Cconnector. If MODEC = HARDWARE, a "low or 0" onpin 19 (-3 to -15 vdc) will put the ESTeem in theCOMMAND Mode and a "high or one" on pin 19 ( +3 to+15 vdc) will put the ESTeem in the CONVERSE orTRANSPARENT Mode. The factory default isSOFTWARE.

Navigation menu