MICROLOGIX RS232/485 Channel 0

Sorry for the question, but after a discussion and betting with an automation colleague, there was a doubt. In the micrologix manual it says:

''MicroLogix 1400 controllers support the following communication protocols
from the primary RS-232/485 communication channel 0 and the RS-232
communication channel 2''


Does this mean that I can connect both RS485 and RS232 devices? Where do I define that channel 0 will be RS232 or RS485? What exactly does that mean? I understand that RS485 or RS232 are pinout configuration and the connector does not matter as long as it has been previously set.

You must choose one or the other (RS-232 or RS-485) for the wiring. To choose RS-485, you must pick it in the channel configuration 'RS-485, No Handshaking'

Through the same channel
(mini din 8 pin)?

Yes. That is the only channel that can support RS-485.

CH2 (the 9-pin D-shaped port) is strictly RS-232, although either channel can support multiple protocols.

To be clear: the pinout does matter on Channel 0 for the MicroLogix 1100 and 1400 controllers.

On those controllers, Channel 0 is a single serial port with two different electrical transceivers, for RS-232 and RS-485.

Pins 1, 8, and 2 are connected to the RS485 chip.

Pins 7, 4, and 2 are connected to the the RS-232 chip (Tx, Rx, Gnd) along with Pins 3, 6, and 5 (RTS/CTS and DCD).

To use the RS-485 port for DH485 or Modbus RTU, you configure the port for "485 Network - No Handshaking", which enables the RS-485 transceiver. All the other settings enable the RS-232 transceiver.

The other models of MicroLogix (1000, 1200, and 1500) used Pins 1 and 8 for a +24v DC auxiliary power supply to power up interface modules like the Net-AIC, Net-DNI, and Net-ENI. Such modules are either unpopular or unnecessary in the modern MicroLogix product line.