If your project requires a standard PLC with great functionality, expandability, and great networking capacity, then you may want to look at the AB MicroLogix 1400 (1766-LWA...). The MicroLogix 1400 (ML1400) is an upgraded version of the MicroLogix 1100 (ML1100), and is one (1) of two (2) MicroLogix controllers which come standard with an embedded ethernet port. The MicroLogix 1400 is also one of the only MicroLogix series of controllers which allows on-line editing. But what separates the ML1400 from it's little brother ML1100, is that the ML1400 can be complimented by a whopping seven (7) expansion modules vs. four (4) for every other MicroLogix controller. If your application requires more than seven (7) expansion modules, you're still in luck: You can stagger almost an infinite number of 7-slot racks via CIP communications via the embedded ethernet port - for very fast and reliable remote rack communications.

Micrologix 1400 Communications Options:

Serial Ports (2) - DH485 - DF1 Full/Half Duplex - DF1 Radio Modem - Modbus RTU Slave - Modbus RTU Master - DNP3 Slave - ASCII

Ethernet Port (1) - 10/100 Mbps Full/Half Duplex

The typical configuration which I use the ML1400 is in a simple PLC/HMI combination. Usually, the HMI that I utilize is a Panelview Plus 1000 (10" TFT, with ethernet). I employ a simple four (4) position, unmanaged ethernet switch and I assign the ML1400 an IP address of 192.168.1.10 for example, and I assign the HMI IP address of +10 off of the PLC. The ML1400 has many communications options other than the embedded Ethernet/IP port. The two (2) serial communications ports can be configured for a host of protocols: DF1, RS485, and even Modbus RTU. It's amazing that I still have customers who request a SLC system with Modbus communications. To accomplish Modbus comms., with a SLC system, I must employ a 3rd. party expansion module from ProSoft. I can utilize a ML1400 with exactly the same I/O for about 1/4 of the cost of the SLC system, while taking up about 1/4 of the footprint.

The scan time of the ML1400 is another attribute that makes this PLC an attractive option. I utilized two (2) ML1400's to run an entire automated robot assembly line. I used one (1) ML1400 to run the external commands of the Nachi robot via discrete I/O and also to run the HMI (Panelview Plus 1000), and I utilized another ML1400 to run the automated conveying systems and RS232 communications from the various barcode readers for traffic control and sorting. My client was astounded with the simplicity of the design and also with the relative inexpensive hardware that I utilized. My client originally wanted to utilize a ControlLogix system; however, I was pleased to offer a cheaper alternative which was just as effective. Because of the small, powerful, and relatively inexpensive ML1400, this project was a home-run!