Connecting to DH485 SLC 5/02 with generic USB to RS485 converter?

[abishur]

Hi all, I have a SLC 5/02 that's been gathering dust for the past couple years that I want to have some fun with. The only problem is I don't have a 1747-UIC cable (which yes can be purchased easily enough on eBay).

My question is can I use any USB to RS485 converter? Is it RSLinx that adds the DH485 protocol on top of RS485 physical electrical standard, or does the 1747-UIC have a special chip inside of it that handles the DH485 conversion?

 

[Ken Roach]

The 1747-UIC does DF1 to DH485 protocol conversion onboard.

A general-purpose RS485 converter will not work for the connection you describe.

 

[abishur]

Thanks Ken, I had a feeling the UIC was more than just a USB to RS485 converter.

 

[CTC-GUY]

Would This Work? I Use The USB-Serial Adapter Always

 

[GaryS]

RS 485 and DH 485 are not the same at all
RS485 is an upgrade for of the RS232 everything else is the same. it allows you to communicate to device up to about 3,000 ft. RS232 is good to about 50 FT max
RS232 voltage level is 5v ref to grd RS485 is 12V 2 channel A & B "ON" or 1 A is + with ref to B
"OFF" 0 A is - ref to B
Also SLC5/02 requires a 1747-PIC to program ( From the manual) I have worked with some of these older units and they can only be programmed with the PIC cable. I have tried the newer cables and they don't work.
I keep one here just for backwards compatibility

 

[Mickey]

Would This Work? I Use The USB-Serial Adapter Always

No, the PIC driver requires a real serial port on your PC.

 

[jvdcande]

It should be possible, but only with a data-driven RS232-485 converter. This means that the converter only uses a three-wire connection on the RS-232 side. Some converters use CTS or another control line to switch over from receive to transmit and these are a no go.

And yes, you can even add an USB-RS232 converter, but that one is even trickier. The only converter I have had success with was the one geniusintraining got me. You should contact him here on the forum, he's very knowledgeable in these matters.

 

[GaryS]

Yes the PIC driver only recognizes Com 1 or Com 2
and all USB adapters are assigned automatically by you system depending on the USB port.
you can go into the system and reconfigure the port
first you have to delete com 1 or com 2, if it will let you and after that you plug in and registers the USB to serial adaptor, reconfigure it to be com 1 or com 2
but a better you is to install a VM or VPC machine and install the programming software in it.
by default the VM machines assigns the com ports com 1 and then com 2
in the configuration of the VM machine find the USB adapter you want to use and assign it to com 1 or com 2
Some times you can use the UIC cable and it will work depending on the firmware
VPC has worked for me the PIC driver will only work with Com 1 or 2 or the DOS preassigned address for com 1 or 2 in the pic configuration.

 

[Mickey]

Yes the PIC driver only recognizes Com 1 or Com 2
and all USB adapters are assigned automatically by you system depending on the USB port.
you can go into the system and reconfigure the port
first you have to delete com 1 or com 2, if it will let you and after that you plug in and registers the USB to serial adaptor, reconfigure it to be com 1 or com 2
but a better you is to install a VM or VPC machine and install the programming software in it.
by default the VM machines assigns the com ports com 1 and then com 2
in the configuration of the VM machine find the USB adapter you want to use and assign it to com 1 or com 2
Some times you can use the UIC cable and it will work depending on the firmware
VPC has worked for me the PIC driver will only work with Com 1 or 2 or the DOS preassigned address for com 1 or 2 in the pic configuration.

And the PIC driver worked with a USB to serial adapter after you did this??

Sorry,I guess I would have to see it to believe it.

 

[GaryS]

it's been a long time but I remember using it on old SLC brick nothing else would connect.
the addressing is what's important
Com 1 or Com 2 or you can use the DOS com address I would have to look up the number
if you assign it above 2 it can't fine it. Remember the PIC was designed to work in DOS only some of the early versions with lower firmware revs. can only be programmed using a PIC you can message in and out with anything
it is a bit tricky to setup the VPC should work.