You never "RESET" MB 1, therefore it is always on and you can never see a Positive Transition (Coils and registers are retained over a power cycle). Either change MB 1 to a Direct Coil instead of Reset Coil, or place a Reset Coil at the end of Rung 4.
Context : I quickly created a VisiLogic file this morning, which is dedicated to control two brushless motors (axis entitled Y1 & Y2 in the ladder) run into position & torque mode. The communication is established via CANopen protocol.
Issue : I have troubles with my program execution at the very beginning, in my main routine 😭 after the CAN bus configuration is achieved.
My program launches correctly, but the execution fails when i want to send an NMT command to my two VFDs ==> The timer "TE 0" does not launch when the PLC scans the net. Logically, it should work, but technically, it does not... What am i doing wrong ? 🤔
I share the code with you so that you can visualize the issue. I know my topic is not really clear so i can give you further informations if needed.
P.S. : Oh and by the way, i am new to ladder programming... and programming in general actually... So if you find something weird or poorly written in my code, i would be really thankful if you can give me a feedback about it
Does anyone have a solution for this or a file that actually works and explains what changes must be done?
I have tried to configure the gateway using the example file from https://support.unitronics.com/index.php?/selfhelp/view-article/bacnet-gateway-as-slave as a base, but it never works.
We have customers that have bought this gateway believing they can communicate with BACnet just as easy as they can with Modbus.
Unitronics help desk could not help, they just sent me the same sample files I already have. Any help is appreciated.
1. PID regulator, or Control Loop, is a complex.
- Controller (PLC)
- Sensor/sensors (temperature, humidity, speed, pressure, flow, vacuum, etc.)
- Actuators (vents, compressors, heaters, coolers, pumps, etc.)
- Communication channels for sensors and actuators (0-10V, 4-20mA, PWM, VFD, etc.)
All this with it's timing (conversion delay, step response, acceleration/deceleration, etc.)
2. Changing any of control loop elements will lead to change of P, I, D and other Control Loop parameters.
This means that with an optimal Control Loop parameters (current PID parameters set) you can replace any element for the same to have Control Loop working with the same efficiency.
3. Change element type/model will require Control Loop parameters change to have Control Loop working with the same (or very similar) efficiency.
4. Change PLC model leads to change of many parameters in Control Loop.
As a result - you can use old parameters as estimate, than make manual PID tune, or run PID AutoTune.
PID AutoTune will warrant that resulting Control Loop parameters will be optimal for current configuration.
Hope this information helps to make Control Loop (PID) at new PLC as effective as an original one.