1747-uic?

I did a search and read what had been written but did not see a fix to my problem.

Am using a 1747-UIC mod in a laptop with no serial port (not my choice!). Everything works fine when I go to a SLC 503 direct, online without trouble.
But I have one small network that has a DTAM unit and a 503, via AIC mods. Who's active sees the DTAM and the computer without fail, but the SLC 503 is sometimes seen and sometimes not. You'll see it get "X" out every few scans. When I attemp to go online, it finds no PLC at the node? I did set the "Latency Timer" down to 1, but this did not help. Is there a link to an A-B site with known problems listed?

I have no trouble with the system using my old laptop and a PIC unit.

Thank You for any help. Glad I found this place, looks great!

http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/$$Search/?OpenForm

Check here, you may find some help with your problem!

Thanks Randy. But I could not find an answer. I am working with my local AB guy. Should we come up with a solution, I'll report it here.


Has ANYONE been able to get online with a 503 through a AIC Link coupler using the 1747-UIC converter? I see AB lossing even more market share over this. I was able to buy a $30 "over the counter" USB-Serial converter for my Automation Direct project, and had no trouble at all!

AB is stuck with a protocol (DH485) which is very dependent on character timing. Modbus is able to take all sorts of variance between the characters of a message in stride. DH485 freaks out. The software has to be able to get DIRECTLY at the communication chip to ensure this timing. It can't use the good services of Windows trying to handle stuff. When this protocol was devised (I've been told it was by Nippondenso) there was no hint on the horizon of a CPU NOT having direct control of the communication. Could you in the early eighties forsee USB and Windows trying to help? The 1747-UIC tries its best, with a full fleged CPPU taking in DF1 and doing a protocol and electrical change in the adapter. The PIC box just did an electrical change, from RS-232 to RS-485 with handshaking lines. At some point we're just going to have to replace these DH-485 networks. It's a very outdated system.

(ICOM had marketed a software interface from programs written in 'C' so that they could communicate with the DH-485 network. This was back a way - the internal comments in the software source referred to the 'Data Highway' as a 'Data Sidewalk'. Obviously they weren't too impressed.)

The good old days, ICOM was the best.
AB Needs to try a little harder, the UIC interface is not cutting it...

[Well, all I can say is that Rockwell/AB is one day going to see the err of their ways. I have some UIC modules but have not used them with a link coupler. I can readily see where AD is able to offer such a bargain for a converter that will do the job as opposed to the UIC which runs in the hundreds for the same job. Reality check for Rockwell/AB? Maybe!

Click to expand...

Just to make sure we compare apples to apples:

AD USB to serial just an interface converter, it does nothing with protocol - byte in, same byte out.

A-B 1747-UIC is Not just a USB to serial converter, it is a protocol converter, it actually converts DF1 protocol to DH485 protocol. it actually has an additional mictropocessor inside to do this protocol conversion.

Old 1747-PIC was just an electrical interface converter, PC did all protocol handling. With USB PC can't handle DH485 any longer.

UIC is more like 1747-KE module.

Contr_Conn said:

Just to make sure we compare apples to apples:

AD USB to serial just an interface converter, it does nothing with protocol - byte in, same byte out.

A-B 1747-UIC is Not just a USB to serial converter, it is a protocol converter, it actually converts DF1 protocol to DH485 protocol. it actually has an additional mictropocessor inside to do this protocol conversion.

Old 1747-PIC was just an electrical interface converter, PC did all protocol handling. With USB PC can't handle DH485 any longer.

UIC is more like 1747-KE module.

Click to expand...

But I never had a 1747-KE not work.
Seems this UIC mod is about as bullet proof as a paper towel, or programming thru channel o...