Which products are affected?
ESP-HMI1-P (HMI Designer Version 1.1 and higher)
What happens?
Although the connected device (a system bus device) sends process data, these are not displayed by the keypad.
When does the problem occur?
If in the Project Manager of the HMI Designer the process data channels of several devices are configured in such way that they have the same transmit identifier, the keypad will not display the data of telegrams with these identifiers. This is also the case if only one of the devices sends a telegram with this identifier.
Generally it is not permitted to assign the same transmit identifier to several system bus devices since this leads to communication errors. When the HMI project is compiled, the HMI Designer does, however, not detect that the same transmit identifier has been assigned to several devices. Therefore, the HMI Designer does not display an error message or warning. According to the standard the HMI Designer sets the identifiers of each device depending on the device address (bus node address). This means that different devices can only have the same transmit identifier if the identifiers have been modified manually.
Possible diagnostics?
For every device the transmit identifiers set are to be checked in the Project Manager. For this purpose mark the corresponding device and open die Device properties dialog via the menu item Edit>Properties. Click on the <More> button in this dialog. Select the process data channel to be examined (e. g. CAN In/Out 1) in the Parameter dialog which is open now and click on the <Edit> button. The transmit identifier of the device is in the RX field.
Short-term measures / recommendations?
Ensure that the same transmit identifier is not used by another device if the transmit identifiers of the devices in the HMI Designer are configured manually.
In the HMI Designer all process data and parameter channels that are not used for the communication between keypad and device (system bus device) are to be deactivated.
Evaluation:
Due to an incorrect setting of the transmit identifiers of the devices (system bus devices) in the HMI Designer the data of telegrams with these identifiers are not displayed by the keypad. This function restriction is detected during commissioning at the latest. In the HMI Designer the identifiers of the devices are modified manually rather rarely.
