Ken Roach
Lifetime Supporting Member + Moderator
The Channel 1 DB-9 port on the MicroLogix is definitely a very ordinary, garden-variety, bog-standard, off-the-shelf, general-purpose, run-of-the-mill, standard RS-232 serial port.
If the connection between the HMI and the DM Board is literally just two wires, it is very probably "2-wire RS-485", which is a different voltage and transceiver standard. It also definitely requires a third conductor, which is sometimes the ground plane or even earth ground.
You could get a 1763-NC01 breakout cable that allows the MicroLogix 1400's Channel 0 (which combines the terminals for an RS-232 transceiver and an RS-485 transceiver in the same physical plug) to connect to the two data conductors.
Or, you could get an RS-232 to RS-485 converter, which often provides isolation between the devices. The A-B 1761-NET-AIC is popular with the MicroLogix.
But I don't think you should try to hook anything up at all until you understand the roles of the "master" and "slave" and have information about how the HMI driver is logically configured.
If the connection between the HMI and the DM Board is literally just two wires, it is very probably "2-wire RS-485", which is a different voltage and transceiver standard. It also definitely requires a third conductor, which is sometimes the ground plane or even earth ground.
You could get a 1763-NC01 breakout cable that allows the MicroLogix 1400's Channel 0 (which combines the terminals for an RS-232 transceiver and an RS-485 transceiver in the same physical plug) to connect to the two data conductors.
Or, you could get an RS-232 to RS-485 converter, which often provides isolation between the devices. The A-B 1761-NET-AIC is popular with the MicroLogix.
But I don't think you should try to hook anything up at all until you understand the roles of the "master" and "slave" and have information about how the HMI driver is logically configured.