HMI development on TM172DCLFG

[POPE3909]

Hi,

I'm developing HMI screens on the TM172DCLFG (touch screen version), largely based on the HMI screens from the M172 built-in B/W display. Except for changes in font size and buttons (from physical to touch-based), the base HMI code and structure are the same.

However, the performance on the DCL screen is very laggy, especially on pages with a lot of information. For example, the alarms page uses 'Sets' with 'Set_AlarmsName' and 'Set_AlarmsStatus,' totaling 70 variables in each set (see screenshots attached).

Please refer to the attached video for reference. Notice the lack of lag on the M172 PLC for the same 'Alarms' page compared to the very laggy performance on the DCL touch screen.

On simpler pages like the clock adjust page, the DCL performs quite fast as shown in the video.

What do you think is causing the laggy performance? Is it the RS485 speed or the processor? Upon checking the hardware, the DCL touchscreen has the same speed ARM Cortex M3 processor with up to 120MHz, so it should be able to handle what the M172 PLC does. I'm using the touchscreen as the master and the M172 as the only slave on the RS485, so the network load is minimal.

[FedericoM]

Hello,

the delay is caused by modbus communication, each @PLC.variable read by the M172 requires a modbus message.

If you want to optimize the speed you should manage all the modbus part from programming, using multiple R or W messages.

If you define a global variable in the Display part (only for this target), the variable can be used both in programming and display.

[FedericoM · Accepted solution]

I usually define a CASE linked to a different modbus read, every 0.5sec I managed a different read.

If a write is required from Display, I set a trigger which will manage the write.

In case of R/W set, if you want to keep the @PLC.variable syntax, you have to limit the number of parameters shown per page.

[POPE3909]

Hi Federicom,

As you suggested, I limited the number of variables per page and it works fine. Thanks for your explanation and clarification.