Explain ( FAX #: (303) 439-8651 ATT: Nick )

<nbucska@pcperipherals.com>

Hello;
     Check out this web site:
http://www.m-system.co.jp/english/index.html

Sound like you’re to convert a powered device to a loop powered device. That’s not easy, because most 4 wire device are that way due to power consumption. So if you device used 50ma at 24vdc to power up your loop would require a 300vdc power source at 4ma on the loop side.

If you got stuck replacing an old 2-wire device with a new 4-wire device and only have a 2-wire cable in place then your SOL. However if you have a shield in that cable and don't mind the possibility of noise interfering with the signal most 4-wire devices can be wired as 3-wire devices.

4-wire
+24vdc-------------------Black
+4-20ma------------------White
-24vdc------|------------Shield
-4-20ma-----|

Hope that's enough Rope....