Westermo MX-69 - Manual (Page 4)

8 6119-2001
Hints
Some hints on set-up of the MX-69.
1. Check the cable between your RS-232 interface and the RS-232 on the MX-69.
The RS-232 interface on the MX-69 is configured as DCE (Data Communication
Equipment). See suggestions on page 9 of cable configuration to connect eight
RS-232 equipments to a MX-69.
How to check whether the equipment is DTE or DCE:
• Power up the unknown equipment and ensure that nothing is plugged into the RS-232
interface. Using a multi-meter, first measure the voltage on pin 2 of the connector
(male or female) with reference to ground on pin 7 (25 pole connector) or on pin 5
(9 pole connector, PC standard). Then measure the voltage on pin 3 in the same way.
The pin with the most negative voltage will be output pin and will identify the device
as DCE or DTE.
25 pole connector RS-232-C
• If the most negative voltage is on pin 2: the device is DTE.
• If the most negative voltage is on pin 3: the device is DCE.
9 pole connector, PC standard
• If the most negative voltage is on pin 3: the device is DTE.
•
If the most negative voltage is on pin 2: the device is DCE.