Moxa CP114EL-I Serial line adapter
The Processor Unit is equipped with a Moxa CP114EL-I serial adapter board. The board provides four serial lines. The serial lines are connected using a large D-connector on the rear side of the Processor Unit cabinet.
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The Moxa CP114EL-I serial adapter supports RS-232, RS-422 and RS-485 (both 2 and 4-wire).
The connections to the board are made using a converter cable with four 9-pin male D-connectors. The converter cable is supplied with the Processor Unit.
•  Manufacturer: Moxa
•  Manufacturer’s website: http://www.moxa.com
Unless otherwise specified, this cable must be provided by the installation shipyard.
Note
Observe that long runs of unshielded cable will pick up noise easily. This is because the RS-232 signals are not balanced.
Maximum length for an RS-232 serial cable is typically 60 meters with 2400 bps data rate, however this depends on the cable quality. Always check the cable manufacturers specifications for the actual "shunt capacitance". A common figure is 47.5 pF/m, which gives a maximum cable length of about 50 meters.
Even though a standard exist for RS-232 pin configuration, certain manufacturer may still choose their own connector pins for the various signals used. In order to make the RS-232 connection to your peripheral device work properly, you must always consult the relevant instructions provided by the device manufacturer.
Pin assignments
Moxa CP114EL-I 9-pin D-connector converter
Pin RS-232 RS-422 RS485 (4–wire) RS485 (2–wire)
1 DCD TXD-(A) TXD-(A)  
2 RxD TXD+(B) TXD+(B)  
3 TxD RXD+(B) RXD+(B) Data-(B)
4 DTR RXD-(A) RXD-(A) Data-(A)
5 GND GND GND GND
6 DSR      
7 RTS      
8 CTS      
9        
Minimum cable requirements
•  Conductors2 x 5 x 0.5 mm²
•  ScreenOverall braided
•  Voltage: 60 V
•  Maximum outer diameterDefined by the plugs and/or the cable gland
If you need to install a very long cable, increase the cross section.