Integrating Mitsubishi with Desigo BMS

Hello,

Does anyone got some experience integrating the Mitsubishi VRF system with the Desigo BMS using a PXC 100 ED. 

The issue I`ve got is that the BMS keeps overriding the setpoint entered by the user using the Mitsubishi local interface. Does anyone had the same issue?

Many Thanks,

Some ideas

Change the AO to Release Command in the TYPE pin

Change the address to B=[DEVINST][AVAL, OBJINST](P=15)

_CJ

Hi,

What type of point are you using in the PX to write the setpoint out to the system? If you are using an AO, check that the Heartbeat time property is set to 0. If the property has a time period set, then it will write the setpoint out to the system at that time period, and will update/overwrite the changes made via the local keypad - the most recent change wins. By having the time period set to 0, the PX will only send the value out to the system on a change of value (or maybe if the PX is restarted).

I'm not sure of your application, but are you trying to achieve local keypad adjustment during occupancy periods, with some sort of setpoint reset via the PX each day? If you're not doing anything like that, you could remove the AO that's writing the setpoint, and map the same BACnet reference to an AI to simply read the setpoint value.

Regards,

I am using an AO to write the setpoint. The heartbeat time is set to 0. As you said the most recent change wins. I can't remove the AO point as the user can adjust the setpoint via the AV system which communicates with the BMS which in turn sends the required signals to the AE200. If the user changes the setpoint on the local touchscreen, we need to keep the last values set by the user on the local touchscreen. Is it right to say that if the PX only send the value out to the system on a change of value, each time, the user will change the setpoint on the touchscreen, the BMS setpoint will be updated and override the value entered by the user on the local touchscreen, 

The main issue is that whenever someone uses the local keypad, the block Binary Output doesn`t get updated (which make sense as it`s a Binary Output). So we can see the value changing from On to Offin the status block. Then,  because the Air conditioning Unit block BO is still sending the same value, the local keypad get back to the state shown in the Binary Output. 

For example,

1. the Air Conditioning Unit BO is sending an On command.

2. The User would like to use its local keypad and switch off the AC

3, The Unit ON OFF status goes OFF

4. Because the Air Conditioning Unit BO is still sending an ON Command, the local keypad reverse to ON.

5. The Unit status ON OFF goes ON

Many Thanks 

Hi,

Thank you for your reply,

I`ve now configured all hearbeat to 0 whether its a BO or a setpoint setting. I still got the same issue and the Mitsubishi local keypad keeps going off.

Is there any type of logic we could add to avoid this. 

Many thanks for your support,