Interesting [?!] UIC issue..

Hi all... here's a head scratcher...

Setup:

S/W: RSLogix 500 / RSLinx Lite - recent purchase.
H/W: Old SLC-500's (fixed I/O) and Micrologix 1500's
Cables/Adapters available: PIC w/C10, PM02, UIC w/C13
Laptop: Customer's Compaq Armada 1750 w/serial & USB, running W2K - clean install/patched to the yingyang...
Port settings: COM1-default, USB-COM5 (autoset by UIC drivers)

Problem: communications

Issue matrix:

Laptop COM1 -> PIC/C10 -> SLC500 - OK
Laptop COM1 -> PM02 -> Micrologix - OK
Laptop USB ->UIC/C13 -> SLC500 - OK
Laptop USB ->UIC/PM02 -> Micrologix - Nope!

Above tried with several PLC's of each type (to rule out a single bad PLC).

According to theory , the 4th setup should work. What's puzzling is that the PM02 cable works directly from the COM port, but not the UIC. The UIC works while talking to the SLC 500... but not the ML1500's

Symptoms of the latter include alternating flashing on the UIC i.e. USB led goes solid, then off as DH485 led flickers and UIC tries to open a link. UIC is set to address 2, COM1 set to 0, PLC's default to 1.

Luckily, I have the serial option for now, so I can get work done...

Having recommended the UIC, only to find there are issues making it work with the newer PLC's places me in a bit of an embarassing position, as the customer will be a) migrating the PLCs away from the discontinued SLC's to ML1500's, and b) anticipate the next laptop that an executive gives back to their IT dept. will only have USB ports.

Any ideas re settings?

Thanks in advance... Ross

Protocol ?

That's an excellent set of facts and situation matrix; good work stating the problem.

One factor that can be inferred but should be explicit is which protocol driver you are using in RSLinx Lite for each situation, and which protocol is enabled in the MicroLogix 1500.

What I *think* you are saying is:

RSLinx PIC -> Laptop COM1 -> PIC/C10 -> SLC500 (DH485) - OK
RSLinx PIC -> Laptop COM1 -> PM02 -> Micrologix (DH485) - OK
RSLinx DF1 -> Laptop USB ->UIC/C13 -> SLC500 (DH485) - OK
RSLinx DF1 -> Laptop USB ->UIC/PM02 -> Micrologix (DH485) - Nope!

If in instance #2 above you are actually using RSLinx DF1 to talk to the MicroLogix 1500, then instance #4 won't work because the MicroLogix 1500 is set for DF1.

Also, I think there's a switch on the 1747-UIC that allows you to select the RS-485 jack or the RS-232 plug. If that switch is broken or in the wrong position you might see this behavior.

If it's neither of those things.... well, I dunno. If you can find another 1747-UIC you can find out if it's a hardware problem, but I have not heard of any firmware/driver/operation problem that makes the RS232 port on the UIC not work.

This only can happen if MicroLogix port forced to DH485 or DF1.

I think PLC does it automatically at the power up - if DH485 detected, it will be Dh485, if not DF1

Try: COM1 -DF1- PM02-Micrologix

Thanks for the responses...

Darn... I KNEW that I forgot to mention something...

Restating the above, here are the drivers I'm trying to use in each case:

RSLinx PIC -> Laptop COM1 -> PIC/C10 -> SLC500 (DH485) - OK

I figured out that PIC wouldn't work in anything but the situation above.

Therefore, I set up two DF1 driver configs set to start manually, as req'd. and named to help me keep things straight. First:
RSLinx DF1-COM1-> Laptop COM1 -> PM02 -> Micrologix (DH485) - OK

Then:
RSLinx DF1-USB -> Laptop USB ->UIC/C13 -> SLC500 (DH485) - OK
RSLinx DF1-USB -> Laptop USB ->UIC/PM02 -> Micrologix (DH485) - Nope!

Switch does get moved to proper position for either 9 pin RS-232 port or RJ-45 DH-485

I'm still learning about the Micrologix... am I getting bitten by a default PLC port configuration? In other words, is there a super-secret sequence of [power-up?] events I'm not following?

Thanks...

In all but one of your connections the end protocol to the PLC is DH485. Only in the direct connection from COM1 to the MicroLogix is the DF1 going all the way to the PLC. Now - can the same Micrologix figure out that you (using the UIC) are now speaking DH485 to it? That I don't know. Contr_Conn mentioned about a 'power-up' detection of the protocol on the MicroLogix. Try your direct connection (out COM1) to the Micrologix using the PIC (DH485) protocol. See if it communicates using that. Then all your examples would be equivalent.

Thanks Bernie...

I think your analysis is correct - Using the PIC driver causes the COMM 0 LED to flash like mad, but the PLC doesn't show up in RSWho... Just my luck to have a PLC version of DeNiro (...You talkin' to me? )

Have tried pressing/releasing COMMS pushbutton under cover in different combinations with/without power cycling - DCOMM LED goes off or comes back on normal - solid...

So, what (if anything) can be done? (Feel free to jump in, folks...)

Thanks... Ross

Because you are able to use the RSLinx DF1 driver and a 1761-CBL-PM02 cable to connect to the MicroLogix 1500, that indicates that the MicroLogix 1500 is configured for DF1 protocol.

The MicroLogix 1000 can automatically detect and switch between DF1 and DH485 protocols, but the MicroLogix 1500 and 1200 cannot. Instead, the MicroLogix 1200 and 1500 have a "Default Comms" button that switches Channel 0 back to DF1 Full Duplex with defautl serial port settings.

The immediate fix for you would be to change the MicroLogix 1500 serial port to DH485 protocol, and always use the PIC driver on your PC that has a real serial port.

This, unfortunately, will tie up your serial port so other applications can't use it (the PIC driver has a long and storied history as a serial port hog).

What I do on PCs that have only USB ports is carry two different USB devices; a 1747-UIC for DH485-only applications, and a Keyspan U19 USB/RS232 converter for all other drivers and applications.

Protocol versus Signalling

Time for another round of a topic that confuses a lot of A-B beginners: the difference between protocol and signalling.

DH485 protocol can run on RS485 wiring, which is its typical implementation in old fixed SLC's and 5/02 controllers.

DH485 protocol can also run on RS232 wiring, which is how it was implemented in MicroLogix controllers 8 or 9 years ago. MicroLogix are often connected to DH485/RS485 networks using 1761-NET-AIC isolator/converters to convert to RS485 wiring, but you can also connect to them directly with the same RS232 serial cable that you use for DF1 connectivity.

This has led to a LOT of confusion, as many folks assume that if they are using a 9-pin RS232 serial port, they must also be using DF1 Full Duplex protocol. That's not the case.

Don't worry, you're in good company. Get a Keyspan converter for your toolbox and you'll be a happier guy.

Thanks for the refresher, Ken -

I cut my teeth back on PLC-2's, 3's, and early 5's (Who can forget the lovely T-50?) and went through some of the same protocol vs. wiring issues also with Ethernet vs RG-58 vs UTP... I'm just having to re-learn smaller processors (and their trade-offs)... And I do remember the grief that PIC's can give... One example: more than once their high current draw on laptop batteries has ambushed me...

I'd prefer (going foward) to try and limit the amount of @#$%^! that I have to lug - so settling on USB & the UIC seems like a great idea... simplify...

This project will have me bouncing back and forth between the old and new PLC's, and the laptops I have available (with or without COM ports) only have one USB port - with power limitations (who wants/needs to lug a powered hub?).

Cycling RSLinx on/off/on while moving the slide switch on the UIC between ports would eliminate further confusion for the customer.

So...my remaining point of confusion is that the UIC supposedly talks native DH-485 - how can I persuade the ML1500's to play along?

Thanks... Ross

In RSLogix 500, go to Channel Configuration -> Channel 0 and change the driver from DF1 Full Duplex to DH485 (you will have to scroll up).

This will allow you to always use the RSLinx PIC driver on the computers with genuine RS232 ports, and always use the 1747-UIC on the computers that have USB ports only.

Thanks Ken...

A bit more clarification is needed...

Problem with AB/RS has always been sequence of events.

A) As things stand now, UIC is not reporting back to RSLinx that ML1500 is connected to it.

B) Using Channel Configuration requires that the project file be open - which in light of no comms is an offline situation - and I can't go online because of A) .... an apparent Catch-22...

"What we have here is a failure to communicate..."

Why do I get the feeling that I'm missing something painfully obvious?

Sorry to be a pain... Thanks

You got online once, you can get online again !

Go get the computer with a real serial port. Use the RSLinx DF1 Full Duplex driver to go online with the controller using RSLogix 500 software.

Change the serial port Channel 0 from DF1 Full Duplex to DH485 while online. The software will warn you that you will lose communications; go ahead and accept the change.

Now you can go back to your PC with the 1747-UIC and you can get online using DH485 protocol.

Again, I can't speak highly enough of the Keyspan U19 and HS19 converters. They're inexpensive, small, and have the best stability and functionality of any USB/RS232 converter on the market. I use mine for serial line analysis and interpreting Modbus on the fly through the included traffic monitor utility.

Hello, I tried to connect Panelview 550 with dh485 protocol(rs232 port) and Micrologix 1500 LSP B. I was easy programming the panelview, and the plc, but I had to change the configuration of channel 0 (PLC). So I changed it from DF1 to dh-485, like this: "Change the serial port Channel 0 from DF1 Full Duplex to DH485 while online. The software will warn you that you will lose communications; go ahead and accept the change."
Then, I connected the plc with the panelview and they wordked perfectly. But after a few minutes y tried to change the configuration of channel 0 to DF1 again, pusshing the "COMS" button. I did it, but I made all this procedure again and I can't use the rs232 pc serial port. I probe it all diferent ways, and I think that this port is damaged. So I don't want to use another rs232 port to change from Df1 to dh-485. I'm afraid.
I hope you help me, I woould thank you.

Jhoan

Questions about channel 0 configuration of Micrologix 1500

Hello, I have a similar problem, when I tried to configure the com port of Micrologix 1500 (DF1 to Dh-485) I think I damaged the RS232 pc port. I didn't use 1747-pic or 1761-net-aic, just direct conecctión with a panelview 550.
Thank you.

Connecting directly to your Panelview's RS232 port should not have damaged your PC's port.