I had a robot freeze and tp screen go blank. I powered it back up and now have a SFDI 21 alarm. it also looks like there is an emergency system red led lit up on the computer board.
SFDI 21 ABNORMAL STATUS
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ASIJordan -
October 22, 2019 at 11:19 PM -
Thread is Unresolved
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I believe the DCS uses SFDI11 and SFDI21 as the dual channel input.
That error suggests there is a problem with the SFDI21 half of the dual channel.
I would check the integrity of the external circuit connected to this where it has been allocated to.
- Emergency stop board.
- Safety IO Mini Slot board.
Failing that, it may well be a hardware issue.
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thank you. the problem was a faulty cable. we fixed that now have a E-stop board not found. is there something I have to do on the pendant or did we wire something wrong?
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Last time we had E-Stop board not found, it was actually caused by the +24V External fuse on the PSU. You might check that before you start swapping boards.
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I believe that's what it is but we keep blowing that fuse every time we power up the robot
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Be sure your pinout on the SFDI connector is correct. We had that issue when we ran SFDI 11 to SFDI 21 instead of SFDI 11 to 0V and SFDI 21 to 24V EXT. If yours has been working and was just a cable issue, i would not expect the pinout to have changed, but it is always possible something got crossed or mismatched. This just indicates you are drawing too much voltage, either a short or using the wrong voltage/ground.
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I believe the DCS uses SFDI11 and SFDI21 as the dual channel input.
That error suggests there is a problem with the SFDI21 half of the dual channel.
I would check the integrity of the external circuit connected to this where it has been allocated to.
- Emergency stop board.
- Safety IO Mini Slot board.
Failing that, it may well be a hardware issue.
I'm having the same SFDI21 alarm. But I know my wires are making the connection because I can perform a full clear of all alarms. I think it is a timing issue. I think it's not seeing the signal fast enough. Can I open that up from a setting within the pendant?
Any advice would be appreciated.This error came out of the blue. I was teaching points like normal. Picked up pendant and saw it on 2 of my robots. The other 2 were unaffected.
Thanks in advance!
Esrevnad -
The timing of the signals must be within 200 ms. Generally that isn't an issue unless there is something wrong with your system.
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As HawkME has mentioned, this discrepancy is set at 200ms (this is mentioned in the DCS manual).
You may want to look further into the Safe I/O consistency check as this area does have an adjustable discrepancy time (between signal 1 and signal 2) and I am sure this area is intended to tackle discrepancies.
The majority of times I have seen discrepancy exceed these values is due to:
- Age of wire/resistance differences in the cable providing the signals.
- Users providing signals from unsuitable relays which produce bouncing instead of using forced guided.
So it is better to try and rectify these problems instead of using timing to circumvent them as you may find you are constantly fire fighting as the system ages.