Safety RS Studio v 30,31,32 Rockwell View Designer V7.02

[dahnuguy]

5370 PLC with a 440C CR30 22BBB safety PLC.

5 Estops wired in series back to the safety input.
Using pulse outs to power estop contacts.
2 sets of NC contacts on each estop.

Machine is new install, safety was working in shop and onsite.

Now all the safety input blocks are solid green with the SOF1 blinking slowly from grey to green as if it only needs a reset.

Give it reset, reset input goes green.

No change in SOF1.

There are also 2 light curtains and 4 scanners , each set are connected in the safety PLC using AND blocks and then all 3 sets of AND are connected to SOF1.

2 estop input blocks AND2 light curtains AND 4 scanners = SOF1

Reset input is on SMF3 and SOF1 has SMF3 input defined as its reset. SOF1 is manual reset.

Any ideas why the safety PLC will not reset? It worked for awhile. 2 different PLCs are doing this now. Was just one.

I played with increasing the discrepancy and input filters on the safety input blocks but nothing seems to make any difference.

 

[James Mcquade]

do you have the program as it was installed?
if so, do a comparison and see what has changed.
bubba may have gotten into the plc.
james

 

[dahnuguy]

No one here tonight but me.
I found that if you leave the reset button pushed for slightly more than about 1 second, the safety blocks just error and will not reset.

But if I use a shorter reset, like 500ms, the safety PLC resets but the alarm code needs to see the safety reset and also reset the alarm.
Which takes just over 1 sec.

So I used a clock bit to pulse the reset twice at less than 1 second each, for each time the reset button is pushed.

No operator is going to hit reset twice and make sure the lights turn green etc.

 

[dahnuguy]

so many 2s
its real 2s day

 

[andrewwei]

E-stop, LC, and Scanner have their own block right? Not the AND instruction, but instruction specific for LC, E-stop with pulse test.

 

[dahnuguy]

E-stop, LC, and Scanner have their own block right? Not the AND instruction, but instruction specific for LC, E-stop with pulse test.

Yes they do have their own individual input blocks.
They are then ANDed to one output.
Holding the reset too long will cause the safety PLC to ignore the reset.