Need converter


Thread Starter


I have an analog signal that is scalable from 4 to 20 mA. I need to have this signal converted to RS232, what type of converter do I need?
There are a number of vendors with suitable analog to serial devices, although much more common are analog to RS-485 rather than RS-232, and it is becoming more common to see Ethernet and USB as well as RS-485.

B&B Electronics sells the Advantech 'Adam' line (although they are RS-485), but have their own model #232SDA12, which is RS-232, but 0-5 VDC input, and not natively 4-20 mA. However, it is an easy matter to drop the 4-20 mA output across a 250 ohm resistor to give you 1 to 5 volts DC.
What you need to looking for is analog input modules which will accept mA input type and range +/- 20mA (such as ADLink ND-6017). In addition, you also need a RS-232 to RS-422/485 converter (such as ADLink ND-6520).

Jasen Lee
Service and Support
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