Internet PLC Forum

General => Technical support => Topic started by: vsingh on October 02, 2004, 11:52:25 AM

Title: COMM1 pinout
Post by: vsingh on October 02, 2004, 11:52:25 AM

I know that COMM1 on MX1616+ has only three documented pins. Are the other pins on the connected or are they connected to power and ground in some undocumented manner ?

Title: Re:COMM1 pinout
Post by: support on October 02, 2004, 03:34:47 PM

Only pin 2,3 and 5 are used on the T100MD+ PLC. T100MX+ PLC uses pin 4 to get power from the host for its opto-isolated serial interface so pin 4 is also required.

For T100md+, all other pins are not connected to power or ground. Pin 1,4,6 are shorted on board and pin 7 and 8 are shorted on board. These are to provide loop backs for the RTS/CTS pair and DTR/DSR if you use a 9 wire conductor. These signals are not used by the PLC but some host computer/modem etc may want to see these signal being looped back in order to allow communication to take place.