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Modbus PLC to VFD serial cable

Modbus PLC to VFD serial cable

Modbus PLC to VFD serial cable

(OP)
Hi Guys,

Can someone help me figure out which of the below pins I need to connect.

I am using modbus RTU on a 2 wire RS485 link, and I want to connect the (master)PLC's rs232 to the (slave)VFD's RJ45.

Thanks,
Andy
--------------------

Automation Direct
Direct06 D0-06AR PLC
RS232 port

Port 2 Pin Descriptions
1 5V Power (+) connection
2 TXD Transmit data (RS-232C)
3 RXD Receive data (RS-232C)
4 RTS Ready to send
5 CTS Clear to send
6 RXD- Receive data (-) (RS-422/485)
7 0V Power (-) connection (GND)
8 0V Power (-) connection (GND)
9 TXD+ Transmit data (+) (RS-422/485)
10 TXD- Transmit data (-) (RS-422/485)
11 RTS+ Ready to send (+) (RS-422/485)
12 RTS- Ready to send (-) (RS-422/485)
13 RXD+ Receive data (+) (RS-422/485)
14 CTS+ Clear to send (+) (RS-422/485)
15 CTS- Clear to send (-) (RS-422/485)


Altivar 61 VFD
RJ45 modbus port
 
Pin Signal
1 Not connected
2 Not connected
3 Not connected
4 D1
5 D0
6 Not connected
7 VP (2)
8 Common

RE: Modbus PLC to VFD serial cable

It's dificult when manufacturers use different labels.
I would start by connecting a pair to DB-15 (DL port 2) pins 9 & 10 with the shield to pin 7.
Jumper RTS to CTS pin 11-14, 12-15, you may not need this but it won't do any harm.
It looks like the pair from DB-25 go to RJ45 pins 4 & 5 but I don't know which is +
I wouldn't connect to pin 7 (positive?) or 8 (ground) unless the manual recommends it.
If you need to receive data back from the VFD I think you need to also connect the DB-25 TXD and RXD together 9-13, 10-6

If you have a laptop with RS-232 port connect it's RXD to pin 10 and ground to pin 7 and you will be able to monitor the traffic using a terminal program.
Start off with your baud rate at a low setting e.g. 1200, it's more forgiving. Play with the Stop and Parity settings until you see it start to make sense, then you can speed up.
Hope this helps
Roy

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