James Mcquade
Member
hi all,
i'm sorry, but this is a little long winded.
i discovered today that someone years ago created a bunch of formulas incorrectly and it has left me in a bind. some how , some way they left off part of the sequence.
i am tracking the weld joint of a belt conveyor. the pusher system clamps the belt and pulls is from 3" to 18" based on the spacing of a prox switch located on each end of the stroke. the purpose of this is to turn on an alarm in the hmi application to signal the operator to inspect the weld joint.
since the line is based on inches per minute, i need to time the line for 60 seconds. what i am having trouble with is how to time the system for that period.
the cycle is clamp, move forward ands make a prox, dwell, unclamp, retract and make a prox, dwell and start over.
i have the logic down for everything and it works, but the inches per minute are not where they should be. the hmi displays 10" but we are actually moving 13.5" per minute.
i track the movement based on the cycle stroke which is 4.5" and is constantly checked for accuracy but changes based on product.
the problem is that when the belt speed changes, the pusher stroke time is automatically changed and the formula to figure the cycle time is off causing the number of cycles to be off.
this is a plc5 system and any suggestions as to how to approach the programming of the unit will be much appreciated.
thanks in advance,
james
i'm sorry, but this is a little long winded.
i discovered today that someone years ago created a bunch of formulas incorrectly and it has left me in a bind. some how , some way they left off part of the sequence.
i am tracking the weld joint of a belt conveyor. the pusher system clamps the belt and pulls is from 3" to 18" based on the spacing of a prox switch located on each end of the stroke. the purpose of this is to turn on an alarm in the hmi application to signal the operator to inspect the weld joint.
since the line is based on inches per minute, i need to time the line for 60 seconds. what i am having trouble with is how to time the system for that period.
the cycle is clamp, move forward ands make a prox, dwell, unclamp, retract and make a prox, dwell and start over.
i have the logic down for everything and it works, but the inches per minute are not where they should be. the hmi displays 10" but we are actually moving 13.5" per minute.
i track the movement based on the cycle stroke which is 4.5" and is constantly checked for accuracy but changes based on product.
the problem is that when the belt speed changes, the pusher stroke time is automatically changed and the formula to figure the cycle time is off causing the number of cycles to be off.
this is a plc5 system and any suggestions as to how to approach the programming of the unit will be much appreciated.
thanks in advance,
james