To speed up communications, try the following method.
The condition can also be improved as described below.

<Baud rate>

Increase the communication speed (baud rate).
When changing the baud rate, be sure to change the settings on both the V series and the temperature controller.
Setting location: V-SFT editor [System Setting] → [Temperature Controller/PLC2Way Communication] → [Temperature Control/PLC2Way]

<When multiple temperature controllers are connected>

When multiple temperature controllers are connected, activate the communication with all temperature controllers.
This eliminates recovery confirmation accesses to stations where communication is down.

<Temperature control/PLC2Way table>

Use the [Temperature Control/PLC2Way Table] without placing temperature control memory directly on the screen.
Use [Temperature Control/PLC2Way Table] to transfer the temperature control memory to the internal memory and place the target internal memory on the screen.
If [Temperature Control/PLC2Way Table] is already used, separate the table for each station.
For more information about [Temperature Control/PLC2Way Table], refer to "How to read or write data between the temperature controller/inverter and the PLC memory or internal memory at regular intervals".