Allen Bradley 5/40E Serial Connection

Hi,

I intend to connect an Allen Bradley 5/40E controller to a PC serially. The planned wiring is a 100 ft cable to connect to the PLC's DB-25 connector on one end and a PCI card (with 2 serial DB-9 ports) on the PC as the other end.

I hope I can use the RS-422A protocol to accomplish this (considering the length) and use Kepware KepServerEX as the OPC server to acquire data from the PLC.

I'm fairly new at this and was confused as to why the PLC manual mentions the 1770-KF2 module in the connection as an adapter.

Shouldn't the above serial wiring work independent of the adapter?

I will appreciate an early reply on this.

Thanks!

According to the PLC-5 selection guide:
PLC-5/40E catalog number: 1785-L40E
User Words Max: 48,000
I/O Max: 2048
Communication ports: 1 Ethernet, 2 DH+ or
Remote I/O (Adapter or Scan )

As you can see there isn't a serial port, the DB25 connection is an ethernet port.That's why the KF-2 was referenced, it allows a pc to connect to a DH+ network serially.
Why not use ethernet? much faster, and you will not need any special adapters at the PC, and 100 feet is well within the range limitations of standard Cat-5 ethernet wiring.

Then use RsLinx OEM instead of the Keepware for your OPC server.

My reference was the Enhanced and Ethernet PLC-5 Programmable Controllers User Manual pg 25. Next to the Channel-0 port it says:

"25-pin D-shell serial port; supports standard EIA RS-232C and RS-423 and is RS-422A compatible. Use this port with ASCII or DF1 full-duplex, half-duplex master, and half-duplex slave protocols. The port's default configuration supports controller programming using DF1 point-to-point, 2400 bps, no parity, one stop-bit, BCC error check, no handshaking"

Channels 1A and 1B are the DH+ ports.
Channel 2 is the 15-pin Ethernet port.

Shouldn't it work with the 25-pin serial if I were to use RS-232 using a 50-ft cable converted to DB-9?

Can you please explain or point to a basic tutorial that can explain how to use RSLinx to use this link to capture data via serial and save as a simple CSV text file.

Thanks a bunch!

You're correct about the ports, my bad.

Here is a link using RSLinx and DDE to log data to an excel file. It's for a SLC, but the PLC will be almost the same.

http://forums.mrplc.com/index.php?download=134

or take a look at this one

http://forums.mrplc.com/index.php?download=543

In reality you may get away with using a 100ft cable with serial but if worried then use RS422 converters http://www.bb-elec.com/RS232.asp

Since you know you may be using RS422 may just want to get a PCI card for that purpose: http://www.bb-elec.com/product_multi_family.asp?MultiFamilyId=11&Trail=2&TrailType=Top

The rest would be using Kepware, their website and manuals should get you started on that. You can download it if you do not have it yet, the download version will work a couple of hours at a time without the license.

rsdoran said:

In reality you may get away with using a 100ft cable with serial but if worried then use RS422 converters http://www.bb-elec.com/RS232.asp

Since you know you may be using RS422 may just want to get a PCI card for that purpose: http://www.bb-elec.com/product_multi_family.asp?MultiFamilyId=11&Trail=2&TrailType=Top

The rest would be using Kepware, their website and manuals should get you started on that. You can download it if you do not have it yet, the download version will work a couple of hours at a time without the license.

Click to expand...

No need for a converter ( on PLC5 side), PLC5 serial port can be configued for RS422 see PIC.
Also I agree with Ron, I have gone as much as 150 ft without problems using RS232 ( good cable , with no noise)

First things first...

Whats the Ethernet port doing on that PLC5?

Just curious, I realize you are already determined to use the serial port...

Like Ron and Mickey
I could also cite a few anecdotal cases in which exceeding RS232 worked just fine...If you do that, be very meticulous with wire routing and terminations.

I could also cite a few that didn't work very well after just a short time in service due to poor craftsmanship by the installer, cable degradation, etc...

422 gives you distance, much better noise immunity, and most of all, multi-drop potential. You can add other nodes to the SCADA later quite easily.

Is your PCI serial card 422 configurable?

Compare it's settings closely with that of the PLC5 book when configuring the port.

Or, use a BlackBox converter at the PC and it's standard serial port. Their stuff, as already cited is very solid, even in a pretty rugged environment.

JMHO,
PEC

422 gives you distance, much better noise immunity, and most of all, multi-drop potential. You can add other nodes to the SCADA later quite easily.

Click to expand...

Not really, 422 has a capability of one driver connecting to 10 recievers, in other worlds one master to up to 10 slaves. RS485 is the one with true multi-drop capabilities. It does allow longer distances.

http://www.rs485.com/rs485spec.html

Thanks for the correction, Ron.

I think I got my 485 memories crossed up with my 422 ones...CRS, huh?

I decided to go ahead and buy a 55ft cable to use with RS232C and somehow manage the length constraints. But I'm afraid I might have made a mistake in the cabel pin assignments.

I had referred to pg G-2 of the same manual I mentioned above:


Will this work or do I have to get it changed to as the one mentioned posted by Mickey?

Secondly, is an OPC server really essential? We've got a Kepware server running with drivers for a Siemens PLC. We checked with Kepware and they say that we just need to install the AB drivers for this PLC to get it to work. So all I need is the DF1 drivers to get a start with the serial connectivity?

alias said:

I decided to go ahead and buy a 55ft cable to use with RS232C and somehow manage the length constraints. But I'm afraid I might have made a mistake in the cabel pin assignments.

I had referred to pg G-2 of the same manual I mentioned above:

Will this work or do I have to get it changed to as the one mentioned posted by Mickey?

Secondly, is an OPC server really essential? We've got a Kepware server running with drivers for a Siemens PLC. We checked with Kepware and they say that we just need to install the AB drivers for this PLC to get it to work. So all I need is the DF1 drivers to get a start with the serial connectivity?

Click to expand...

Yes that cable should work:


Yes DF1 driver for PLC5

Phew! Thanks guys!

Really, really appreciate all the help!