20mA current loop serial data communication ?
20mA current loop serial data communication ?
(OP)
Hi,
I need to extend an old 20mA current loop (serial data communication). I have an rs232 to CL converter that does not have an external power supply. This works fine for short distances but now I have moved the machine and it has stopped working. The wire I am trying to run it through is about 200m (650ft.) and is about 8ohms back and forth.
The current loop has 3 wirers: IN, OUT and a 0 (Zero).
I rely need a solution to fix this, any ideas?
Thanks
I need to extend an old 20mA current loop (serial data communication). I have an rs232 to CL converter that does not have an external power supply. This works fine for short distances but now I have moved the machine and it has stopped working. The wire I am trying to run it through is about 200m (650ft.) and is about 8ohms back and forth.
The current loop has 3 wirers: IN, OUT and a 0 (Zero).
I rely need a solution to fix this, any ideas?
Thanks





RE: 20mA current loop serial data communication ?
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RE: 20mA current loop serial data communication ?
Keith Cress
kcress - http://www.flaminsystems.com
RE: 20mA current loop serial data communication ?
RE: 20mA current loop serial data communication ?
RE: 20mA current loop serial data communication ?
http://www.lab-systems.com/products/fib-opt/afl300...
RE: 20mA current loop serial data communication ?
When links are not properly configured, they will often work over short distances, but not longer ones.
Is it possible to get 4 wires for your link?
Also, for the longer distance I would get a powered device. B&B makes great converters.
http://www.bb-elec.com/Products/Datasheets/232CLDR...
RE: 20mA current loop serial data communication ?
What is the process measuring device, how many wires connect that device to the converter? Did the measuring device to converter distance change or did the converter move with the device? Of the three mentioned terminals, are they connected to the device, just two or are all three used? Describe the RS232 connections, or alternately, at the other end of the 232 link. Is the converter recognized? It would help if you could identify the make and model of both the process device and the converter.
Maybe you could be helped if the problem is more clearly described
Steve
RE: 20mA current loop serial data communication ?
But regarding the 3 wires on the CL, from what i was told is that the 0 (zero) is a combination of the Tx- and Rx-. The other two IN and OUT are the Tx+ and Rx+.
I put a few pictures of the converter. The distance from the Pc to the converter is about 1m (3ft) and the distance fro the converter to the grader is about 200m (650ft). The cable i am running it over is a CAT5 where i use 3 of the pairs. I.e. I use one pear together for the IN, one pair for OUT and one pair for 0.
One thing i am wondering cold it be that i need a better cable?
Thanks a get for taking the time to help me.
RE: 20mA current loop serial data communication ?
Steve
RE: 20mA current loop serial data communication ?
RE: 20mA current loop serial data communication ?