idssteve

Now knowing that PCOM isn't working on 485, we've set up the four PLC's on modbus and the customer is now data logging via SCADA. Extracting the actual log from the SD card is still the long term goal but modbus is working ok, for now. Thanks!

Thanks Joe. I'll PM you.

We will get Unitronics adapter and update. Thanks.

We've only crossed the terminals long enough to try. They are + to 1 and - to 6. We've also tried a different usb to 485 adapter with the other A(+), B(-) designation. Also tried a 9pin to RS422-485 adapter plugged into the laptop's serial port #1. No joy. No voltages exceed 5v so no bias needed? We've returned the SG to the PLC's terminal #3 which is also bonded to earth ground. Can you recomend a vendor that might overnight us a MJ10-22-CS25 and a M90-19-R4? We're having difficulty finding one. Thanks for your efforts.

We're in process to order your adapter and cable but the adapter we're currently trying is a ULinx USOTL4. It's one of those with B(+) and A(-) designations. We've tried both ways but B(+) is tied to RJ12 pin 1. A(-) is tied to RJ12 pin 6. A DVOM confirms idle voltage of +4V on B(+) relative to A(-). Should we need to address bias in this short cable? Also, we're unclear as to where to tie SG. SG is currently tied to RJ12 pins 2 & 5 but we've tried floating it and also tried tying it to PLC's Terminal 3 chassis ground.

Sorry about loosing the last post before finishing. VisiLogic settings are: Select Conntion Type: Serial PC Port: Com 8 Baud Rate: 9600 TimeOut: 4 sec (we've tried everything up to 30 sec) Retries: 3 Communicate with OPLC: Direct Connection We've also tried Within Network (Unit ID) 106

Yes, We're connecting straight from the PC to the PLC. Network to the four PLCs to come later but just want to see direct connection as first step. The PLC's Com1 485 termination jumpers are "on". We've tried "off", also. VisiLogic settings are: Connection Type: Serial Baud Rate: 9600

Thanks for the replies. Ethernet's on the list of possibiltiies. Right now i'm just trying to get a single individual V130 to com with a laptop on RS485. Cable is about 60" long, 26AWG, 6 conductor, Copartner #E119932-U with molded on 6pin rj12. . Info Mode into "Communication", 1. Serial, 1. Com1, shows: Com1 - RS485 Prtcl: Modbus, ign Brk: N Settings: 9600 ,8,n,1,N Tx/Rx: 00000 00000 Silence: 2.50ms Also ... Menu: 5. Setup Modbus RS485 ID: 106

We’re tasked with configuring a PC running SD Card Suite to access SD card data out of four VL130-33-TR20's via 485. But that’s an issue for later discussion. Before getting that far we’re wanting to establish PC connection to each individual VL130s. The only successful PC connection we've accomplished is after setting the Com1 jumpers to 232. Everything seems to communicate well through the VL130's Com1 from the PC's 9 pin serial port in that mode. This PC is a Panasonic CF-30 with built in 9 pin serial port. Setting Com1 jumpers back to 485 the PC is unable to connect to any of the four VL130s. Either via 9 pin serial or by 485. Everything is 9600, 8N1. We’ve tried a serial 232 to 422 converter (BB elect 422LP9TB), a usb 485 converter (AD USB-485M) and a uLinks USOTL4. All old standbys that have served well on many projects, FWIW. We’re preparing to order a Unitronics MJ10-22-CS35 and a M90-19-R4. Unless you have other recommendations? Till those devices arrive, I’d like to see if you guys can recommend anything to check? Thanks.