ericvfsu
Guest
E
My most immediate concern is how to represent my PLC (inputs, outputs & logic) in my electrical schematic that I need to provide to my customer Yesterday. I have other concerns as you will see below.
I am controlling 2 motors. Each motor has a 3 position selector switch (on, off, auto). I have the electrical schematic down for the motor starters, the "on" portion of the 3 position switch, and the "off" portion of the 3 position switch. Pretty simple stuff.
How do I represent the "auto" portion - which is controlled by a PLC?
The input to the PLC is the system pressure provided by a pressure transmitter (mA). The output is to close the relay that provides the signal to the motor starter. Motor A should start when the system pressure is < 270 psi. Motor B should start when the system pressure is < 260 psi (either because motor A did not start or because more flow is needed to keep the pressure from dropping). Both motors should stop when the pressure is > 300 psi. The designation of Motor A & Motor B is switched each time that Motor A is started so that motor/pump life of the two systems is equal.
A further question is how to represent the pressure transmitter (mA) in the electrical schematic? Also, can you recommend an internet available resource that will have me quickly up and programming the PLC (DL05 PLC from Automation Direct using DirectSoft 32 software)?
I understand the logic (in IF ... Then ... sentences - referring to the I/O addresses) needed to accomplish my task, but don't quite know how to translate that into my software (the manual is useless for the task). I am also completely lost on how to read (and scale) my signals from the pressure transmitters.
Help Please!!??
I am controlling 2 motors. Each motor has a 3 position selector switch (on, off, auto). I have the electrical schematic down for the motor starters, the "on" portion of the 3 position switch, and the "off" portion of the 3 position switch. Pretty simple stuff.
How do I represent the "auto" portion - which is controlled by a PLC?
The input to the PLC is the system pressure provided by a pressure transmitter (mA). The output is to close the relay that provides the signal to the motor starter. Motor A should start when the system pressure is < 270 psi. Motor B should start when the system pressure is < 260 psi (either because motor A did not start or because more flow is needed to keep the pressure from dropping). Both motors should stop when the pressure is > 300 psi. The designation of Motor A & Motor B is switched each time that Motor A is started so that motor/pump life of the two systems is equal.
A further question is how to represent the pressure transmitter (mA) in the electrical schematic? Also, can you recommend an internet available resource that will have me quickly up and programming the PLC (DL05 PLC from Automation Direct using DirectSoft 32 software)?
I understand the logic (in IF ... Then ... sentences - referring to the I/O addresses) needed to accomplish my task, but don't quite know how to translate that into my software (the manual is useless for the task). I am also completely lost on how to read (and scale) my signals from the pressure transmitters.
Help Please!!??