PMDX Forum
General Category => SmartBOB controllers and dedicated accessories => Topic started by: uta.alexander on April 27, 2017, 09:17:07 PM
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Firstly, apologies if someone has already asked this. I have not come across anyone so far with this issue.
Secondly, the issue: As a default, my PMDX 424 (details below), on powerup has a logic high signal on the output terminals on 12. Which means that straight away the motor enable, and the two SSRs that drive the spindle and coolant are turned on. From what I have read on the forums, the logic signal should be low to prevent this from happening.
Thirdly: as a result of this, the Real Time Status in Mach4 is giving false readings. For example: after hitting the Enable in Mach4, the output signals on J12 output 1 and 2 are shown to have a logic high signal in the program. However the relays are turned off, meaning there is a low signal.
I am wondering if weather there is something wrong with my PMDX or if it is a simple setup issue. I am aware that the active signal preferences can be changed within Mach itself. However this only affects how the outputs behave After the Enable has be activated in Mach.
Details: Windows 10 home, 64-bit
Mach 4 hobby, build 3233
PMDX 424(110/240AC) version:0.49.237
Motors: 3x Clearpath integrated servo
Any advice or help would be greatly appreciated.
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This indeed sounds like a setup issue, but in hardware.
Your solid state relays should be connected from signal output to + on SSR,
and - on SSR to PCgnd. If you have them connected from PC+5 to + on SSR
and - on SSR to signal, this will cause the sort of inversion that you describe.