AB PLC5/10 DH+ network to RS232/485

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Thread Starter

Denis Pack

I need to connect a Inview 2706-P43R to an AB PLC5/10 on a DH+ network.

I've looked at Prosoft, ADAM, SST, etc and they don't do it. Has anybody got a product that solves this protocol conversion issue?

And before you ask why not go TCP/IP, it's not allowed as the IT department forbids it. It provides great isolation from hackers and such.
 
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Steve Myres, PE

I'm not familiar with the Inview messaging unit, but I'm guessing it displays ASCII string fed from the serial port, with non-displayed
formatting command characters optional. It may be DF1 compatible. If so, you can add a DF1 port to your PLC or SLC, or use a 1770-KF2 to
bridge from the RS232/485 to DH+. I've done this and I know it works. I've used some nice modules from Prosoft for bridging between DF1
and DH+, too.
 
Just because you're running Ethernet communications between your PLC and other devices deosn't mean it has to be the same physical network everyone's PC is hanging on. After all you are running extra cable to get DH+. You could just as easily run Ethernet wire, fiber, etc. and have your own private Ethernet network, secure from the outside world. Tell your IT people to think outside the box.
 
Just because you're running Ethernet communications between your PLC and other devices deosn't mean it has to be the same physical network everyone's PC is hanging on. After all you are running extra cable to get DH+. You could just as easily run Ethernet wire, fiber, etc. and have your own private Ethernet network, secure from the outside world. Tell your IT people to think outside to box.




 
Even if TCP/IP was allowed in your production system, you couldn't get it into a PLC-5/10; that's the smallest Classic PLC-5 with only a DH+ port.

What I know about the InView message displays is that they can communicate using ASCII simplex or using an ActiveX in RSView (which was actually packaging Modbus commands !), both over RS-232 or RS-485. If you installed a DH+ to RS-232 device, the output would be DF1 protocol, not ASCII.

I know that the InViews were slated to have DF1 protocol added to them later this year; that would make them compatible with the 1770-KF2 or 1785-KE, as well as the 1761-NET-ENI Ethernet interface or 1761-NET-DNI DeviceNet interface.

Considering the costs of those old comms modules, you might consider just using a SLC-5/04 and having it's serial port talk to your InView displays; especially if there are several.

Or, trade in that PLC-5/10 for a PLC-5/11 or 5/20 and use it's serial port in User Mode with some 1761-NET-AIC isolators.

Good Luck,

Ken Roach
A-B Seattle
 
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