MAGNET POWER SUPPLY SYSTEM 9100
37
DANFYSIK A/S - DENMARK.
The default serial setting is:
8 BIT DATA, NO PARITY AND 1 STOPBIT and baud rate 115200.
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 has control signals.
3.3.3
Termination using RS 422m or RS 485
As standard there is 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 for both the local and the remote line.
The external resistor is preferable.
Hint. 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 multi drop 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). The 1K resistors increase the noise immunity eliminating noise to be
treated as commands thereby flawing the first character after being addressed.
NOTE!
None of the two serial lines have control signals (hand checking). Use the
XON/XOFF protocol if necessary.
