I'd like to interface an inverter with Gateworks GW5220. The inverter has an RS232 port shown below and GW5220 has a 5-pin RS232 Serial interface. The GW5220 serial connector is labeled as follows:

  • Pin 1: GND
  • Pin 2: RX1/CTS
  • Pin 3: TX1/RTS
  • Pin 4: RX2
  • Pin 5: TX2

I'm making a cable that runs between the GW5220 and the inverter. I have a CAT6 cable with a T-568B RJ45 jack at one end that connects to the inverter. At the other end are exposed wires which will connect to their corresponding pins on the GW5220. The problem is I don't know what signals go with what wire on the CAT6 cable.  Can someone help assign the the GW5220 pins to their colored wire on the CAT6?
Inverter RS232 Connection: Inverter RS232 Connection

GW5220 RS232 Connection:
GW5220 RS232 Connection


If a specific pinout not mentioned in your inverter's manual, then RS-232 serial over an RJ-45 (8P8C) connector frequently uses the rollover cable format, also called Yost cable or Cisco console cable.

The RJ-45 pinouts for this type of cable (table copied from the previous Yost.com link) are:

FUNCTION                    DTE  DCE
------------------------    ---  ---
CTS (clear to send)          1    8
CD (carrier detect)          2    7
RX (receive data)            3    6
GND (receive ground)         4    5
GND (transmit ground)        5    4
TX (transmit data)           6    3
DTR (data terminal ready)    7    2
RTS (request to send)        8    1

The inverter is most likely a 'DCE' device (as it isn't a computer/terminal).

I'm not sure why the GW5220 has two sets of RX/TX pins; maybe that's for an alternate mode (RS-485 serial)? I assume the pins function as GND/CTS/RTS/RX/TX when in RS-232 mode.

(Note: RS-232 doesn't usually use a twisted-pair cable, but if that's what you have, the Yost.com article recommends rewiring it to pair 3-4 and 5-6, instead of the typical Ethernet 3-6 and 4-5.)

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