Created Date: July 20,2011

Created by: bcarlton

1. Present practice usually has all wired conditions which cause/allow an output to run should be active ON to the PLC. In that way if there is a wire break the system will go to an OFF condition.

2. If all your conditions are ok does the output start automatically or is some type of 'start ' action my an operator required?

Created Date: July 20,2011

Created by: RonR399

1. Present practice usually has all wired conditions which cause/allow an output to run should be active ON to the PLC. In that way if there is a wire break the system will go to an OFF condition.

2. If all your conditions are ok does the output start automatically or is some type of 'start ' action my an operator required?

Some of the sensors are not available in NC, that is why some are NO.

some of the NO's are actually backup for the NC's.

an operator is required on location to restart. the operator could check the HMI screen to see what caused the shutdown before restart.

this operation uses a 6 cyl engine running on Nat gas and the engine

speed is controlled by pipeline pressure to keep the pressure within limits.

it is a very complicated operation.

thanks for the code example. I will not be able to try it until tomorrow evening.

.

Created Date: July 21,2011

Created by: johnaden

What are the potential dangers if the motor failed to stop when a fault occurs?

A PLC is not recognized as adequate for critical or hazardous applications. You may want to at least consider a hardwired back up shutdown circuit, and use the PLC to show which fault initiated the shutdown.

John

Created Date: July 21,2011

Created by: RonR399

What are the potential dangers if the motor failed to stop when a fault occurs?

A PLC is not recognized as adequate for critical or hazardous applications. You may want to at least consider a hardwired back up shutdown circuit, and use the PLC to show which fault initiated the shutdown.

John

there is a pressure switch(lo & hi) wired directly into the shutdown annunciator(Altronic). the engine's magneto is shorted out and the gas valve is shut off.

Created Date: July 21,2011

Created by: RonR399

What are the potential dangers if the motor failed to stop when a fault occurs?

A PLC is not recognized as adequate for critical or hazardous applications. You may want to at least consider a hardwired back up shutdown circuit, and use the PLC to show which fault initiated the shutdown.

John

the company I work for sent their "geologist " to a 5 day training on plc programming and now he is the "go between " for the SCADA

system designer and the company and is also the local "tech " when there are issues with the SCADA.

I have spent 99.9% of my life(58 yrs old) working with electronics/electricity

and I can do programming with Visual Basic and I did the LOGO! proramming for the engine and pump controls on the system and I am not allowed to

do anything more with the system unless absolutly required.

Also, they do not have a full time "pump operator " and when it needs a re-start ANY of the "truck drivers " are asked to re-start the pump.

they will not listen to me at all.

what do you think?

Created Date: July 20,2011

Created by: RonR399

I would like to explain what I need to do and see if there is a way to do it with the "click " plc.

I will have several inputs that can shut down the pump because they are fault indicators(most nc, some no). I would want to be able to latch the FIRST fault so I would know where the fault orginated.

I do have an input that indicates the motor is operating so no faults are required unless the motor is running.

if someone has an example program that would be great.