Well CRAP,
Here I go having troubles again. While I wait for a proper board to build the error monitoring relay set-up I'm working on getting all 3 axis' wired to BOB and Scorpion output board, also adding a pair of wires at servo drive connector CN I/F which are to go to the relay board.
I brought out a wire from pin 9, this is the one that has to be grounded for drive to accept pulse & sign input, when ungrounded it activates the drive "inhibit". This wire is to be ungrounded by the relay board at the same time as an E-stop in Mach 3 for the "double safety" effect. That seems to be working as expected because I have the first (X) axis wired and even though the drive isn't alarmed it doesn't respond to jog commands with the wire from pin 9 ungrounded, but when it is grounded the servo motor jogs as it should, so far so good.
I also brought out a wire from pin 26, the drive manual says this is the error/alarm output. The way I read the manual it says this output should be "hot" (Vcc) when drive is OK but transistor turns off when drive is in an error/alarm state. This is the output that is to be the "key" to the relay board, Vcc when drive is OK and 0V when drive is alarmed. Well, it's hot all the time no matter if drive is alarmed or not!
I can check between ground and pin 26 when drive is OK and get 21.5 vdc, (still don't know why BOB is getting 24 vdc but puts out 21.5 vdc but so far it hasn't been a problem) but if I disconnect an encoder cable the drive alarms with error 22, (as it should) but the output from pin 26 is still 21.5 vdc !! The alarm out of the drive doesn't seem to be working as manual says. I've double checked to be sure my wire is on pin 26 (it is), if this alarm output doesn't change state I don't have anything to "operate" the safety relay board so no need to build one.
I really want Mach 3 to HALT when a drive is in an error state and I think this is a necessary thing but if the alarm output of drive doesn't work I don't know how else to pull it off.
Just in case any of you servo drive experts should ask this is how I have connector CN I/F wired ;
pin 5 to S+ from Scorpion
" " 6 to S- " "
" " 7 to D+ " "
" " 8 to D- " "
" " 9 to safety relay board (ground to run, open to inhibit)
" " 26 to safety relay board (should be hot with no drive alarms, 0V when alarmed)
" " 11 to BOB 24V
" " 3,12,28,29 & 30 + cable shield all tied to ground at BOB
Just to sum up, the alarm output from pin 26 is NOT turning on & off depending on drive being alarmed or not. Is it possible the transistor in the drive is bad or do I have something wrong again?
Rick