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Pin 4 /RX_REM
For default serial settings, see section 3.3.1.1 UART HW SET UP (Esc<BAUD)
The communication is done by transmitting characters in ASCII code terminated by
CARRIAGE RETURN. The termination characters from the Power Supply are CARRIAGE RETURN
and LINE FEED.
An ERROR message includes a "?BELL". (Bell = ASCII 7.)
NOTE
None of the serial lines have control signals.
3.3.3. Termination using RS 422m or RS 485
Normally there are no termination resistors connected inside the M-Panel. An external
termination resistor of 100 Ohm must therefore be added at the end of the communication
cable or the internal 100 Ohm resistor must be enabled (short-circuiting strap ST2).
This applies to both the local and the remote line. The external resistor is preferable.
NOTE
This resistor can be placed inside the last DB 25 plug for the remote line and the DB9 plug
for the Local line
When using the RS 485 or the RS 422 line in the multidrop configuration, it is very important
during an address transfer to leave the lines at the "SPACE" state when tri-stated. That is when
the line is not driven by any transmitters at all. The "SPACE" state can be utilized by adding 1K
Ohm resistors to +5 V (non-inverting) and GND (inverting) on both the transmit and the receive
lines. The control module can provide this by short-circuiting ST318-ST321 and ST326-ST329
for the remote line and ST335-ST338 and ST340-ST343 for the local line (use a thin soldering
iron).
NOTE
None of the two serial lines has control signals (hand checking). Use the XON/XOFF
protocol if necessary.
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