Not getting an alarm in RSView32 but PLC is able to see the input??

[drspanda]

Dear All,

I am new to RSView32 and I am with a problem these days.....For the conveyour safety we have beltsway switches installed and the operation of switch should result in stopping the conveyour.

However when the switch actuates and resets very quickly, the conveyour gets stopped and alarm in rsview is not comming...if the switch actuates and resets quickly an alarm is comming...

I have seen the tag confiquration and I found the address is of the field device(I:014/8) in rsview and there it is group A.

Please suggest me how to handle this problem...one way is to modify the ladder logic i mean to set an internal bit and to use that internal bit for alarm..

Is there any other way??

Advance thanks

 

[OkiePC]

It sounds like you have the right idea.

The PLC is fast enough to pick up the short duration input, but the RSView32 tag update rate will probably never be fast enough to read a real input which is only on for a fraction of a second.

Two choices:
1. Expand the pulse coming from the switch to a length of time about twice as long as the RSView32 tag update rate for that scan class. This can be done with a hardwired timer with an off delay mode. The advantage would be that it could help the PLC detect things that it might miss. The disadvantages: The fact that it is hardwired and costs money and time to install, and it will increase the likelihood of picking up every little signal which, in some cases, is not desirable.

2. Use an internal bit and program the off delay timer with the PLC to hold this new bit used by the RSView32 alarm in the on state at least twice as long as the scan class update rate.

Paul

 

[iggy]

I would make it a latching alarm, then you could reset it from the HMI.

RSview tag database there is a box to check that its an alarm so it will be displayed on the alarm banner.
There are a few different ways of showing the alarm on the HMI, but It will only show up on the banner alarm page if it is checked in the tag data base.

 

[OkiePC]

I would make it a latching alarm, then you could reset it from the HMI...

That will do no good if the RSView32 application never "sees" the bit go true in the first place.

 

[robertmee]

That will do no good if the RSView32 application never "sees" the bit go true in the first place.

I think you misunderstood his intent. By latching, you latch the alarm in the PLC with an internal bit and reset the latch with a separate alarm acknowledge bit from the HMI. In my opinion, that's the only way to clear an alarm of this nature. It shouldn't self clear, but should require acknowledgement of some sort, so that the alarm stays present to notify the operator for the reason of the shutdown.

In the OPs case, I:014/8 turns on B3:0/0 (eg). B3:0/0 stays latched until B3:0/1 turns on. B3:0/0 is an alarm in RSView indicating belt tripped. B3:0/1 is a PB or other means from RSView to indicate it is okay to clear the alarm.

 

[drspanda]

Thank You very much..