In today’s article we’ll review the communication ports found on the Allen-Bradley series of MicroLogix programmable controllers.
MicroLogix 1000 Communication Port:
The MicroLogix 1000 includes a single RS-232 serial port for communications. This port is an 8 Pin Mini-Din style.
To convert this communications port from RS-232 to RS-485, an 1761-NET-AIC Advanced Interface Converter can be used along with a Mini-Din to Mini-Din cable.
MicroLogix 1200 Communication Port(s):
The MicroLogix 1200 includes the same 8 Pin Mini-Din RS-232 serial port for communications and programming (Channel 0) as the MicroLogix 1000. However, Rockwell made the opening for the cable smaller, thus requiring users buy new series C cables as the older and larger series A and B cables would not fit.
When RS-485 is needed on Channel 0, it can be converted from RS-232 to 485 by using an 1761-NET-AIC Advanced Interface Converter as well as a Mini-Din to Mini-Din cable.
Four years after the original MicroLogix 1200 release, Rockwell upgraded the line by adding six additional models in 2004. These new models included a second, “Respond Only” 8 Pin Mini-Din communications port on the left side of the unit that was used for either programming or connecting an HMI. Models with the second port simply had an additional “R” (for Redundant port, or Respond only port) added to the end of their catalog number.
MicroLogix 1500 Communication Ports:
The first MicroLogix 1500 processor released, the 1764-LSP, had no communications port of it’s own. Instead, to connect a computer or HMI to a MicroLogix 1500 system the user would plug into a Mini-Din communications port that was located on the MicroLogix 1500’s I/O Base. This Mini-Din Channel 0 port was the same form factor as the serial port as found MicroLogix 1000 and 1200.
When RS-485 is needed on Channel 0, it can be converted from RS-232 to 485 using a 1761-NET-AIC Advanced Interface Converter as well as a Mini-Din to Mini-Din cable.
In the year 2000, Rockwell released a second MicroLogix 1500 processor, the 1764-LRP. This new processor included it’s own isolated RS-232 9 Pin D-Shell (DB) communications port (Channel 1.)
MicroLogix 1100 Communication Ports:
The MicroLogix 1100 comes equipped with an isolated 8 pin Mini-Din serial port (Channel 0) used on all previous MicroLogix models. However, it was upgraded to support both RS-232 and RS-485. The RS-485 connections replaced the pins that previously provided 24vdc power to accessories like the 1761-NET-AIC.
When RS-485 is needed on Channel 0, instead of using a NET-AIC we use a 1763-NC01 cable which allows access to the native 485 pins and coverts the 8 Pin Mini-Din cable to a 5 position Terminal Block.
The MicroLogix 1400 also has a built-in 10/100 Mbps Ethernet port (Channel 1) for messaging, HMI’s, or programming.
MicroLogix 1400 Communication Ports:
1400 is similar to the 1100 in the fact that it comes with the same isolated 8 pin Mini-Din serial port (Channel 0) which supports both RS-232 and RS-485.
Unlike the 1100, the MicroLogix 1400 includes a second non-isolated serial port (Channel 2.) This additional port is an RS-232C 9 Pin D shell DB9.
The MicroLogix 1400 also comes with an RJ45 10/100 Ethernet port just like the 1100 and is used for messaging, HMI’s, or programming.
I hope you find the above details about the MicroLogix’s communication ports helpful.
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