pks digiplan SD2 and SD3 triac drive

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jonnydeen
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1986 Triac PNC, linuxcnc
1989 Senior 3c, Heidenhain TNC155

pks digiplan SD2 and SD3 triac drive

Post by jonnydeen » Sun 11 Oct , 2020 12:35 pm

the understanding i have is that the drives require a 12v step & direction signal to operate. can someone confirm this? does anyone know if there are any available parallel breakout boards that can output 12 rather than 5v TTL? or recommend any other solutions for that matter.

DavidB
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Re: pks digiplan SD2 and SD3 triac drive

Post by DavidB » Sun 11 Oct , 2020 18:54 pm

Have a look in the Triac threads and maybe some others on the board as the usual interface to common BOBs with 5V logic is a resistor and transistor to do the level conversion as IIRC the SD cards are internally pulled up to 12V and you need to pull them low to be active which a simple open collector transistor achieves. It's what I'm planning to do on my Triac as at this point I want to use the SD cards it came with. The information is already on the board as people have done it before and documented it including the resistor value and transistor type.

Some information in this thread http://www.denfordata.com/bb/viewtopic.php?f=47&t=1763

jonnydeen
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Posts: 47
Joined: Tue 09 Jul , 2013 20:45 pm
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1986 Triac PNC, linuxcnc
1989 Senior 3c, Heidenhain TNC155

Re: pks digiplan SD2 and SD3 triac drive

Post by jonnydeen » Tue 13 Oct , 2020 17:29 pm

Thanks for the reply @davidb. So far I've thrown a breadboard together with a pair of 2n2222a and a pair of 3k3 resistors and wired it to the rainbow coloured 16 pin ribbon coming from the triac drive card. Using the triac GSM for reference but it doesn't seem to work for me. I cant even get a voltage between the step/dir pins. And 0v. The contactor is actuated manually as I've removed main pcb and the drives power led is illuminated green so now wondering if there is somthing I'm missing. Do the drives need enable signals?
The gsm manual gives pin numbers for the stepper control ribbon connector but there are no markings for pin 1 so I'm just guessing which one is 1 based on google searches of the same type plugs. Any chance denford didnt stick to any standards in the mid 80s?

DavidB
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Re: pks digiplan SD2 and SD3 triac drive

Post by DavidB » Tue 13 Oct , 2020 19:38 pm

Pin 8 on the 16 way is given as /energise and likely connects to the SD cards /energise input (pin 30 row C) which when pulled low activates the output drivers. You could also step the drives manually to check for power by just pulling the step line to ground.

jonnydeen
CNC Apprentice
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Posts: 47
Joined: Tue 09 Jul , 2013 20:45 pm
Hardware/Software: 1996 Novamill, linuxcnc
1986 Triac PNC, linuxcnc
1989 Senior 3c, Heidenhain TNC155

Re: pks digiplan SD2 and SD3 triac drive

Post by jonnydeen » Tue 13 Oct , 2020 20:25 pm

just so we are on the same page here, ive an old 1986 triac, i know the later triacs have a different layout, so likely the loom will be different. ill try the energise pin anyway and see what happens. assuming i have the correct pin out

DavidB
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Joined: Tue 19 Oct , 2010 16:06 pm
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Re: pks digiplan SD2 and SD3 triac drive

Post by DavidB » Tue 13 Oct , 2020 22:23 pm

Mine is a later Triac PC but it still uses SD2 and SD3 cards but as they don't have the heatsinks so I presume they have newer switching devices that produce much less heat. I've seen SD2 and SD3 advertised with the heatsinks on them so presume they're the earlier design but I haven't seen anything to indicate the control interface or power supply requirements differ between the versions.

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