Electronic Systems Technology ESTEEM192S Wireless Modem User Manual part 2
Electronic Systems Technology Wireless Modem part 2
Contents
user manual part 2
CHAPTER 2
MODES OF OPERATION
COMMAND MODE
CONVERSE MODE
TRANSPARENT MODE
SEMI-TRANSPARENT MODE
HARDWARE MODE CONTROL
CHAPTER 2
MODES OF OPERATION
Revised: 11 Feb 99 2-2
The ESTeem has three major modes of operation,
Command, Converse, and Transparent. This chapter of the
manual describes each one of these modes.
COMMAND MODE
The COMMAND Mode (CMD: prompt) is the default
mode that the ESTeem initially enters on power-up or after
a hardware or software reset. From this mode the user can
command or program the ESTeem. In this mode the user
may access the various program commands to configure the
ESTeem for the specific application. These values can be
stored in nonvolatile memory within the ESTeem by the use
of the SAVE command. The ESTeem reads these setup
parameters stored in memory on power-up or RESET.
When programming in the COMMAND Mode, the user
need only enter enough characters to uniquely identify the
respective command.
Example: CMD:ADD 15 <cr>
This enters the source address of the ESTeem to the decimal
value of 15. The first three letters ADD were enough for
the ESTeem to uniquely identify the command for
ADDress. The number of characters that need to be typed
varies depending upon the command being entered. In
some cases, four or even more letters may have to be
entered in order for the identification to be uniquely
determined. Up to ten multiple commands can be written
on the same line if separated by a colon.
Example: CMD:ADD 15:SETC 2:SAVE <cr>
CONVERSE MODE
This mode allows bi-directional communication from the
input/output device attached to the ESTeem to a destination
ESTeem and its respective input/output device. The
ESTeem will automatically switch to the CONVERSE
Mode 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 the
CONVERSE Mode until the radio link has been broken or
by typing a control character defined by the user with the
COMMAND variable.
The factory default for the COMMAND variable is CTRL
C. You can return to the CONVERSE Mode from the
COMMAND Mode by typing CONV <cr>.
When you are in the CONVERSE Mode the echoing of the
character comes from the ESTeem if ECHO = ON (factory
default) has been programmed in the ESTeem.
Transmitting Data
The ESTeem will transmit data from the CONVERSE
Mode if one or more of the following conditions have been
met.
1. The ESTeem transmit buffer has been filled. The size
of the transmit buffer is defined in the ESTeem by the
PACKLEN variable. This variable is programmable
from 1 to 2000 bytes. Factory default is 2000.
2. The ESTeem receives a SENDPAC (send packet)
character from the RS-232C input data stream. The
SENDPAC variable can be defined from 0 to 255 by
the user. Factory default is 13 (carriage return). The
SENDPAC character is also transmitted by the
ESTeem. In file dump applications the SENDPAC
character can be programmed to be the EOF (end of
file) character transmitted from the sending device (i.e.;
CTRL Z, CTRL G, etc.).
3. Termination control timer. The termination control
timer is enabled by the TERMC (on/off) command.
When enabled, the termination timer starts from the
time the last transmit buffer has been updated in the
RS-232C port. If the termination timer expires before
another character is received or transmitted, the
contents of the ESTeem transmit buffer will be
transmitted. The waiting time of the timer is defined by
the TERMT variable (termination time). The
programming range of the TERMT variable is
10-255ms. Factory default values are TERMC = OFF
and TERMT = 50. It is noted that when the
termination timer is used, the SENDPAC variable is
usually programmed to be a character that is non
occurring in your data stream (i.e.; SENDPAC = 255)
so that premature transmission does not occur.
TRANSPARENT MODE
The TRANSPARENT Mode allows the ESTeem to pass all
data characters (O-255 or 0-FF hex) using 8 data bits.
CHAPTER 2
MODES OF OPERATION
Revised: 11 Feb 99 2-3
To program the ESTeem in the TRANSPARENT mode the
TRANSPARent command must be enabled and switch Bit 8
to ON (RS-232C Setup Switch). The TRANSPARent
command will defeat the SENDPAC and COMMAND
variables and put the ESTeem in the transparent mode when
Bit 8 is ON.
The transmission of the data packets can only be
accomplished by enabling the termination control
commands (TERMC and TERMT) or the PACKLEN
buffer being filled. The value of TERMT should be slightly
longer than the maximum delay encountered during
RS-232C transmission. If this time is set to short, the
ESTeem will truncate your data stream improperly.
When using the TRANSPARENT Mode, data flow control
is by hardware handshaking only. Hardware handshaking is
initiated by enabling hardware flow control (XHF = ON).
The SETCON (Set Connect command) must be used to
define the node that you want to communicate with while in
the TRANSPARENT Mode. When the TRANSPARENT
Mode is enabled you can not communicate to the ESTeem
in the COMMAND Mode unless you use the Hardware
Mode Control line (see explanation this chapter).
To remove the ESTeem from the TRANSPARENT Mode
the 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 MODE
This mode should be utilized when sending a non-ASCII
file and there is a possibility that the SENDPAC character
could be contained in the transmitted data set. Perform the
following prior to programming the ESTeem to initialize the
unit 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 may
not be echoed by the CRT.
ESTeem
-------------------------
ADD xxx xxx = your address
SETC yyy yyy = destination address
TERMC ON
TERMT 10
SENDP 255
EDIT OFF
SAVE
If EDIT is off, and SENDPAC = 255, the SENDPAC
character is disabled. This character when received will not
cause packet transmission and will be passed as normal
data. The TERMC and TERMT commands are used to
transmit the contents of the ESTeem transmit buffer.
Software flow control in this example is still enabled
(factory default XSF = ON) therefore the ESTeem will pass
all characters except the data flow control characters for
Xon/Xoff.
HARDWARE MODE CONTROL
The MODECON (Mode Control) command is provided in
the ESTeem to change the mode of the ESTeem modem
from COMMAND Mode to CONVERSE (or
TRANSPARENT Mode) via a hardware control line. The
hardware line is located on pin 19 of the RS-232C
connector. If MODEC = HARDWARE, a "low or 0" on
pin 19 (-3 to -15 vdc) will put the ESTeem in the
COMMAND Mode and a "high or one" on pin 19 ( +3 to
+15 vdc) will put the ESTeem in the CONVERSE or
TRANSPARENT Mode. The factory default is
SOFTWARE.