micrologix 1500 ethernet

I have a customer that wants to put an existing machine on their Ethernet network so they can go online with the processor from the maintenance office.

The machine has a micrologix 1500 (1764-24bwa) in the main control cabinet as well as a net-aic card. in a remote console they have a panelview 1000 (2711-t10g3) with a aic link coupler.

The network layout is shown on the attached drawings.

Is there an easy (cheap) way to get this system on Ethernet.
Is there some type of network card that could plug into port 1 of the net-aic module?

Double-check the part number of the MicroLogix 1500 controller itself.

1764-LSP has just the single round Channel 0 serial port built into the I/O base.

1764-LRP has another Channel 1 serial port (DB9 style) on the left side of the CPU module.

If this is an -LRP controller, and the Channel 1 port is unused, you could add a 1761-NET-ENI or Digi One IAP or even a simpler RS-232/Ethernet converter (a virtual serial port implementation) to get the controller connected to the Ethernet network.

If it's an -LSP controller the challenge is more difficult, because the Data Highway 485 protocol being used by the PanelView and the MicroLogix can't run over ordinary serial/Ethernet converters.

The usual PC-to-DH485 interface is the 1747-UIC (USB to DH485), but you wanted an Ethernet network connection.

To use Allen-Bradley hardware for this you'd have to go huge with a 1756-ENBT, 1756-DH485, and a ControlLogix chassis and power supply.

Protocolconverter.com has a product they say will work in this application, but I don't have any direct experience with it.

http://www.protocolconverter.com/gw1000-485eip/

Swap it out for a MicroLogix 1100 1763-L24bwa.

There are wifi dongles that plug into an RS232 port to give wireless access and this would probably be the cheapest option if the range is not an issue. A more expensive but better option would be to consider swapping for a CompactLogix which has on board Ethernet and is compatible with the other I-O modules.

Does the NET-ENI allow you to go online over Ethernet or just transfer data back & forth?

The only "change the controller" recommendation that I would endorse would be to put in a 1764-LRP CPU, equipped with a serial/Ethernet converter.

Replacing with a CompactLogix is a very large cost increase just to get Ethernet, not to mention requiring reprogramming. No other MicroLogix would support this type of expansion I/O, so you can't use a MicroLogix 1100 or 1400 to get Ethernet.

Again: the protocol running on the existing serial port is Data Highway 485. It is a token-passing protocol with very tight timing requirements that cannot be encapsulated by common general-purpose asynchronous serial converters.

The 1761-NET-ENI takes A-B controller commands encapsulated in the EtherNet/IP protocol and re-encapsulates them in DF1 Full Duplex protocol. This lets you do online with the controller using the Ethernet Devices or EtherNet/IP driver in RSLinx Classic, as well as send messages to the controller from other controllers or HMIs.

In general, throughput for a 1761-NET-ENI is somewhat less than a direct serial port connection would be. A lot of users think "hey, it's Ethernet, it's got to be fast !" but the serial port is the bottleneck.

General-purpose Ethernet to RS-232 converters do not interpret the Rockwell EtherNet/IP protocol or DF1 protocol, but rather transport packets from a "virtual serial port" on the PC to the physical serial port on the device using TCP/IP. This is called "virtual COM Port Redirection", and would require you to use the DF1 Full Duplex driver in RSLinx Classic. You could not send messages to the controller from other controllers, nor could an HMI access the controller (unless it also had a COM port redirector software, something I have never seen in a conventional touchscreen/HMI device).