Modsak Manual v3.10 - 2.6. Device Identification

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2.6. Device Identification

The Device Identification page is used in slave mode to configure the data sent in response to Read Device Identification (43/14) and Report Slave ID (17) Modbus commands.

2.6.1. Read Device Identification (43/14) command

The upper part of the Device Identification page is used to configure the data sent in response to a Read Device Identification (43/14) command.

The name and value of each identification object may edited in the table. The names are used simply as reminders of what each ID is used for - only the IDs and values are sent in Modbus response messages.

To add a new identification object, enter its ID in the Object ID field and click the Add button. Then enter the name and value in the table.

To delete an identification object, select it using the Object ID drop-down list (or by clicking on it in the table) and click the Delete button.

Object IDs are entered and displayed as 2-digit hex numbers.

Modsak uses UTF-8 encoding for the values in its responses to the Read Identification Command, whereas the current Modbus specification specifies ASCII encoding. If you want the responses to conform to the specification, be careful to use only the ASCII subset of UTF-8 when entering values.

2.6.2. Report Slave ID (17) command

The lower part of the Device Identification page is used to configure the data sent in response to a Report Slave ID (17) Modbus command.

The Report Slave ID command is not well defined in the current Modbus specification. Some devices return binary data in their responses, and some return text.

You may configure a binary response by entering the number of data bytes in the Count, and then entering the data in the table as hex bytes.

You may configure a text response by entering it in the Text field. The text will be sent using UTF-8 encoding.