New PC with Serial Com Port for Communicating with SLC 5/03.

[AutomationTechBrian]

I need to recommend a PC to replace a customer's old Windows 7 computer. The only thing I need to think through is the serial com port to communicate with the SLC 5/03. The old PC is connected to the DB9 connector, so I'm assuming just a standard serial com card, and the cable is probably wired as a null-modem.

A quick scan of the internet... it's hard to find a PC with a DB9 Serial com port. Any recommendations? This PC is located in an office, so going with a fan-less industrial computer might seem a little odd (like the ones at OnLogic.com). Any better sources? The only other consideration is having a 2nd ethernet card.

Thanks.

 

[Mark-]

Use a USB to serial device?

 

[AutomationTechBrian]

Hmmm.... like a Keyspan USB to serial. I guess my first reflex is to wonder if that is rugged enough for everyday industrial use, for a long period of time.

Would you choose it?

 

[KuulKuum]

So I take it that the PC you will be replacing is a "Desktop" variety. You could install a PCIE Serial Port Card.

 

[NetNathan]

I use these... nice long cable.
https://www.automationdirect.com/adc/shopping/catalog/cables_(terminated)/plc_cables/usb-rs232

 

[joseph_e2]

I've been using a Keyspan adapter in an industrial setting for about 13 years with no issues whatsoever. I wouldn't hesitate to recommend it, especially to connect to a 5/03. If that's the oldest they have, the Keyspan will do well. There are some older devices that require a native COM port, though. I don't know of any USB adapters that will work in that case. But the 5/03 is fine with this. At least up to Windows 10...

 

[Mark-]

Hmmm.... like a Keyspan USB to serial. I guess my first reflex is to wonder if that is rugged enough for everyday industrial use, for a long period of time.

Would you choose it?

I have used many over the years, very low cost, to 3x the low cost devices. For multi serial ports I normally go with a Rocketport card and I just ordered a SerialComm for testing. Never really had a problem with any device until a few stopped working when a W10 update was released.

 

[AutomationTechBrian]

I think the PCIe card is probably the way to go. Here's the one I was looking at:

2-Port Serial PCIe Card, RS232/422/485 - Serial Cards & Adapters | Add-on Cards & Peripherals | StarTech.com

2-Port Serial PCIe Card, Dual-Port PCI Express to RS232/RS422/RS485 (DB9) Serial Card, 16C1050 UART, ESD Protection, Windows/Linux, TAA-Compliant

www.startech.com

I should add, we thought the keyspan would not be reliable because of the possibility that the computer might have issues when it is re-booted. I've seen this in the past.

 

[Mark-]

I think the PCIe card is probably the way to go. Here's the one I was looking at:

2-Port Serial PCIe Card, RS232/422/485 - Serial Cards & Adapters | Add-on Cards & Peripherals | StarTech.com

2-Port Serial PCIe Card, Dual-Port PCI Express to RS232/RS422/RS485 (DB9) Serial Card, 16C1050 UART, ESD Protection, Windows/Linux, TAA-Compliant

www.startech.com

I should add, we thought the keyspan would not be reliable because of the possibility that the computer might have issues when it is re-booted. I've seen this in the past.

FYI many desktop motherboards have serial port headers and all you need is a header to slot device.
I purchased this one a few years ago. If you want one make sure it is the correct height for the case.

 

[AutomationTechBrian]

That surprised me. I did not know that. But... if it's SLC 5/03, isn't DF1 RS485 for a connection to Scada-type PC application? I notice RS232 is common supported specification.

But I'm not an expert.

 

[arpus4KM]

That surprised me. I did not know that. But... if it's SLC 5/03, isn't DF1 RS485 for a connection to Scada-type PC application? I notice RS232 is common supported specification.

But I'm not an expert.

the RJ45 is RS485

and the DB9 is RS232. Both can be configured for DH485, but the DB9 can be configured for multiple different types of protocols. It's the physical layer that doesn't change.


Also, I'd second just using a USB adapter. the only time you may run into problems with something not working is if you try to use an adapter that required a heartbeat signal from the PC's db9 port, but if it's a USB adapter going to a serial comm, I haven't ran into an instance that doesn't work yet....

This includes SLC100/150, PLC2, PLC5 (going adapter to 1770-kf2 included to get on dh+ via serial usb adapter), SLC500 (all serial), Controllogix, etc all of them work with either the usa-19hs or the 9300-usbs (rockwells adapter).

 

[AutomationTechBrian]

I remember it's default is RS232 (point-to-point), but longer connections should get changed to RS485. I didn't know the cutoff length, but I just looked it up... About 50ft. So it could be RS232 or RS485. The PC is about 20 ft away from the small PLC cabinet.

 

[OkiePC]

If you have a copy of the RSS file, look at the Channel 0 Configuration. Regardless of the protocol, it is RS232 and this adapter will work:

USB to RS232 PLC Programming Cable Special PLCTalk.net

PLC Cables, PLC Trainers and Industrial Automation Supplies

www.plccable.com

It works fine with Windows 7, 10, 11

If it is DF1, Autoconfigure in RSLinx will work with that adapter, I recommend using Device Manager Advanced Settings to lock in a Windows COM number (I always set mine to COM1)

If the CH0 config is DH485, you can most likely still use that same adapter, but would need to set up the communication driver differently.

 

[arpus4KM]

If you have a copy of the RSS file, look at the Channel 0 Configuration. Regardless of the protocol, it is RS232 and this adapter will work:

USB to RS232 PLC Programming Cable Special PLCTalk.net

PLC Cables, PLC Trainers and Industrial Automation Supplies

www.plccable.com

It works fine with Windows 7, 10, 11

If it is DF1, Autoconfigure in RSLinx will work with that adapter, I recommend using Device Manager Advanced Settings to lock in a Windows COM number (I always set mine to COM1)

If the CH0 config is DH485, you can most likely still use that same adapter, but would need to set up the communication driver differently.

If CH0 is set to DH485, it requires the 1747-uic or I guess he could try to run the PIC instead if it's off a real serial port. The UIC has a DB9 that uses RS232/DH485 specifically for that port configuration.

 

[OkiePC]

I think you can use either the regular DF1/DH485 driver set for a 1747KE device, but I have not personally done that. So, you may be right. Mark sells those too:

Allen Bradley 1747-UIC USB to DH485 PLC Programming Cable

PLC Cables, PLC Trainers and Industrial Automation Supplies

www.plccable.com

But they will ONLY work with DH485 protocol (either RS232 or RS485 electrically)