050809-1944 EST USA
Cammo:
For experimenting set baud rate to 9600, stop bits at 1, no parity, and handshake none. Anything you want to set up as a receiver must be set exactly the same way.
For the first test none of these settings matter.
Test 1. Assume the Fagor RS232 connector is a male 25 pin with pin 7 common. Also pin 1 is probably common. Pin 1 is identified as ground, and pin 7 as signal common. These are usually directly shorted together on many systems. When used pin 1 goes to the cable shield, probably only one end. On HAAS machines pin 7 has a 100 ohm resistor from pin 7 to internal common and machine chassis.
Without sending data measure the voltage at pin 2 ( hopefully TxD, serial output from Fagor ) relative to pin 7. This should be about -9 to -12 volts. If it is not, then check pin 3 relative to 7. If this is -9 to -12 volts, then pin 3 is TxD.
Test 2. Put the meter between common and TxD. Now send data and the meter should read an average near zero ( probably within +/- 1 volt ). If this happens you are sending data.
If Fagor has a 9 pin RS232 connector, then pin 5 is common and either 2 or 3 is TxD.
Pins 2 and 3 on either 9 pin or 25 pin connectors are noarmally always the TxD and RxD pins. If you determine which is TxD by the above test, then the other is RxD. When connecting two devices together you must connect TxD at the source to RxD at the destination, and vice versa. This is based on my above definition of TxD being the transmitter at the end of the connection you are testing.
See what this tells us. If your transmission is very short, then it may appear as a blip on the meter. Then set to baud rate of 110 and try again.
.  |