Which products are affected?
ESP-HMI1-P (HMI Designer version 1.x)
What happens?
Process data telegrams from the keypad to the connected device are not transmitted with the identifier set in the HMI Designer but with identifier 0. The user data of these telegrams can be incorrect. As identifier 0 is not identical with the receive identifier of the connected device, user data is not accepted by the connected device.
When does the problem occur?
If more than 21 devices are created, process data telegrams with incorrect identifier are transmitted as from the 22nd device.
The data transmission via parameter channels is not affected.
Possible diagnostics?
The transmission of telegrams with identifier 0 can be diagnosed with a CAN analyser.
Short-term measures/recommendations?
Unused process data channels of the first 21 devices can be used for the transmission of process data. The project will become complicated, however, as the assignment of device and telegram is no longer clear.
Evaluation:
During commissioning, at the latest, the malfunction of process data transmission under the described conditions will become obvious.
Telegrams with identifier 0 contain information on the communication structure (network management). Due to this function restriction, no further malfunctions of the machine/plant are to be expected, except for the consequences arising from the non-transmitted process data.
An application with more than 21 devices with data exchange between keypad and device via process data channel is rather rare.
