Modbus TCP and/or RTU
Posted: Sun Dec 16, 2018 4:03 am
I am wondering if it’d be feasible for someone to implement the modbus TCP or modbus RTU protocol into QLC?
I keep running into situations where I need to interface with modbus devices at different venues to control house lights and motorized circuit breakers.
Currently Ive been bringing and HMI and a PLC and having to program the HMI UI’s and ladder code for the PLC to create scenes that trigger the house lighting.
As this works.. Its time consuming to setup. Its difficult to make last minute changes or changes on the fly during event. Granted it is posable for me. Ive found its almost imposable for someone else todo even with weeks to prep venue. Little lone on the fly.
My vision is to have the ability to trigger a scene in QLC via a modbus coils and registers. And QLC would be able to trigger modbus coils and or registers.
With modbus integrated into QLC it would open up all kinds of lighting control options such as controlling 0-10v ballast dimming, DAIL lighting control etc.
Right now if I need to control a limited number of 0-10 fixtures Ive been using a dmx 0-10 module connected to the lights or connected to the inputs of a PLC to sequentially turn on motorized circuit breakers.
Even though most PLC’s allow the implementation custom protocols the limitation serial com port bitrate maxes out around 115.2k. So sending DMX512 directly isn’t feasible on a low cost PLC without an expensive add-on module.
It would also give us all the abilities the QLC on raspberryPi has when it comes to the gpio’s. But with far superable input protection and configurations. and the total cost of a fully functional industrial PLC can costs less than the cost of a Raspberry Pi with the all the minimum necessary peripherals need for a raspberryPi function.
Another benefit of using a PLC over the raspberry Pi is that they are almost all UL or CE devices unlike the raspberry pi.
Below is a few links that may help explain what Im wanting to achieve and explain Modbus for those not familiar with the protocol.
Example of Beckhoff’s version of what Id like to achieve.
http://m.beckhoff.de/english/applicat/stage_text.htm
Beckhoff DMX master/slave module.
http://download.beckhoff.com/download/D ... EL6851.pdf
Beckhoff DMX manual
https://download.beckhoff.com/download/ ... 6851en.pdf
Qt Modbus Document
https://doc.qt.io/qt-5.11/qtmodbus-backends.html
Modbus Protocol Document
http://www.modbus.org/docs/Modbus_Appli ... V1_1b3.pdf
Modbus TCP/IP Document
http://www.modbus.org/docs/Modbus_Messa ... _V1_0b.pdf
I keep running into situations where I need to interface with modbus devices at different venues to control house lights and motorized circuit breakers.
Currently Ive been bringing and HMI and a PLC and having to program the HMI UI’s and ladder code for the PLC to create scenes that trigger the house lighting.
As this works.. Its time consuming to setup. Its difficult to make last minute changes or changes on the fly during event. Granted it is posable for me. Ive found its almost imposable for someone else todo even with weeks to prep venue. Little lone on the fly.
My vision is to have the ability to trigger a scene in QLC via a modbus coils and registers. And QLC would be able to trigger modbus coils and or registers.
With modbus integrated into QLC it would open up all kinds of lighting control options such as controlling 0-10v ballast dimming, DAIL lighting control etc.
Right now if I need to control a limited number of 0-10 fixtures Ive been using a dmx 0-10 module connected to the lights or connected to the inputs of a PLC to sequentially turn on motorized circuit breakers.
Even though most PLC’s allow the implementation custom protocols the limitation serial com port bitrate maxes out around 115.2k. So sending DMX512 directly isn’t feasible on a low cost PLC without an expensive add-on module.
It would also give us all the abilities the QLC on raspberryPi has when it comes to the gpio’s. But with far superable input protection and configurations. and the total cost of a fully functional industrial PLC can costs less than the cost of a Raspberry Pi with the all the minimum necessary peripherals need for a raspberryPi function.
Another benefit of using a PLC over the raspberry Pi is that they are almost all UL or CE devices unlike the raspberry pi.
Below is a few links that may help explain what Im wanting to achieve and explain Modbus for those not familiar with the protocol.
Example of Beckhoff’s version of what Id like to achieve.
http://m.beckhoff.de/english/applicat/stage_text.htm
Beckhoff DMX master/slave module.
http://download.beckhoff.com/download/D ... EL6851.pdf
Beckhoff DMX manual
https://download.beckhoff.com/download/ ... 6851en.pdf
Qt Modbus Document
https://doc.qt.io/qt-5.11/qtmodbus-backends.html
Modbus Protocol Document
http://www.modbus.org/docs/Modbus_Appli ... V1_1b3.pdf
Modbus TCP/IP Document
http://www.modbus.org/docs/Modbus_Messa ... _V1_0b.pdf