What is the available SLC505 Ethernet communication Protocol?
I need to communicate to a Siemens TXP DCS.
Is the data ledgible coming out of the CJ45 cat-5 port, or must it first be translated?

It's perfectly legible, if you understand CSP or PCCC!

I have never found documentation on CSP. However, SLC 5/05 runs just fine on the PCCC protocol.

It's a binary protocol.

I'm not sure what protocols the Siemens DCS communicates with. If it's like most DCS systems, it probably wants to talk to almost nothing except itself.

You can certainly get a SLC 5/05 to talk serial protocols with an ASCII I/O card, even if it's the Point I/O variety. And you can get it to talk DeviceNet via a DeviceNet scanner card.

If you can't find a protocol bridge immediately, then work towards getting both of them to speak Modbus because you can almost always get anyone to speak that protocol. For the SLC 5/05, take a look at the Digi One IAP which can talk PCCC ("Allen Bradley Ethernet"), Ethernet/IP, Modbus, Modbus/TCP, and "generic ASCII" protocols. Then just find a way to get the DCS to talk something other than DCS.

If the DCS is using Foundation Fieldbus, Allen Bradley does sell a 1756 (ControlLogix chassis) card that can talk FF. Then you can talk to the CLX chassis using DH+ directly from the SLC 5/05.

Thanks paulengr!
I've been working with Allen Bradley a long time and never heard of CSP or PCCC protocol, so I've got some learning to do.
Attached is a schematic of the network configuration.
This network is currently in place, but the DCS will be upgraded from a TXP to a T3000.
What is the protocol of the communication at the SLC5/05 cat5 port?

Could/would someone please elaborate on PCCC communications or provide a link describing its setup and functionality?
Thanks!

The AB Knowledgebase has documents defining parts of the PCCC Protocol, but for some reason it does not recognize my Tech Connect Contract Login today.

PCCC is far more complicated than Modbus/TCP. That being said, you can still fairly easily hammer out a protocol driver in about a day or two (I did it with Python several years ago).

PCCC is effectively a modified version of DF-1. Download Allen Bradley's DF-1 manual before you try to tackle the PCCC (Ethernet) version as it is simply the standard serial protocol with a modified protocol header (some things are rearranged) and a special "hello" packet before initiating communication.

Here is some documentation on Allen Bradley protocols (Ethernet or otherwise):
http://iatips.com/rockwell.html

Also, you can search for Ron Gage's code which is C code. It is written well enough that with the DF-1 protocol book in hand (that AB does publish), you can easily figure out how to put together the Ethernet packets. A copy is located here:
http://sourceforge.net/projects/abplc5/

Ron Gage's code will reveal the differences between the published "book" format for serial DF-1 and the PCCC packets if you read through it carefully (it is very well written and documented).

Note that Ethernet/IP (the protocol used on ControlLogix-based PLC's) is MUCH more complicated, so don't expect to tackle this one without a lot more time involved.

VERY GOOD INFORMATION.
The question that I have is this:
Is the SLC5/05 communication refered to as AB/Ethernet, or EthernetIP?
The DCS manufacurer that we are attempting to interface with thinks that the SLC5/05 communication protocol could be selected between AB Ethernet, or EthernetIP.
What words of wisdom might I convey in response to their assertion?
If they need to design a driver, or pull one off the shelve, to interface with the SLC5/05s as reflected in my prior schematic, what AB protocol must they convert/translate?
It is very clear to me that this is the forum for which to ask difficult detailed questions such as these, so your insight is appreciated.

There are two protocols, called "PCCC" and Ethernet/IP. Allen Bradley only recently started explicitly naming "PCCC" as such in their ControlLogix documentation, so many vendors call it by various names including "PLC-5 Ethernet", "AB Ethernet", "SLC Ethernet", etc. Some of the newer SLC's and PLC-5's will recognize Ethernet/IP but most of the models more than 4 or 5 years old will only recognize PCCC. It is often possible to upgrade the firmware but I never had this issue as almost everyone supports PCCC.

Within the two protocols, there are multiple command formats. Pretty much the rule of thumb is that there is a "native" format for the PLC-3, PLC-5, SLC, and ControlLogix. Micrologix PLC's seem to speak their own bizarre witch's brew of Ethernet/IP as near as I can tell.

Different PLC series may actually recognize more than one command format. For instance, you might find that a PLC-5 may recognize "SLC" commands, or a SLC may recognize "PLC-5" commands, and ControlLogix PLC's may recognize almost anything (when the backward compatibility tables are set up). However, this ability to understand several command formats is generally poorly documented and best avoided.

So with any given driver/interface, you must make sure that it implements both the protocol you are after (PCCC or Ethernet/IP), AND the particular command format for the PLC in question. Not everyone writing DF-1 (or PCCC) drivers fully comprehends this fact, so frequently you may find compatibility problems if the driver is not specifically meant for the PLC series in question.

All this should be obvious if you read through the publically available DF-1 manual here:
http://literature.rockwellautomation.com/i...rm516_-en-p.pdf

For your purposes, if you really want to understand what the protocol is, skip 95% of the manual. Go straight towards the middle where the commands are documented.

There are a few commands that are NOT documented, and there's a separate supplement for ControlLogix processors (not of interest to you). However, these commands aren't that important in most cases. Allen Bradley does not make them a big secret so all you have to do is ask if you want to know.

As to why Allen Bradley made the whole thing so ugly and complicated..I have no idea. There are major data table differences between the PLC-3, PLC-5/SLC/Micrologix, and Control/CompactLogix families which explains why new command formats were necessary. However, there is really no good reason that they came up with completely new command formats for the SLC and Micrologix line.

Fantastic, comprehensive, and very relevant feedback.
This is more than I could have hoped for.
Thanks paulengr!!!!