Proline Promass F 500 Modbus RS485 System integration
Endress+Hauser 91
Code Name Description Application
16 Write multiple
registers
Master writes a new value to
multiple Modbus registers of the
device.
A maximum of 120 consecutive
registers can be written with 1
telegram.
If the required device
parameters are not available
as a group, yet must
nevertheless be addressed
with a single telegram, use
Modbus data map → 91
Write multiple device parameters
Example:
• Mass flow unit
• Mass unit
23 Read/Write
multiple
registers
Master reads and writes a
maximum of 118 Modbus registers
of the measuring device
simultaneously with 1 telegram.
Write access is executed before
read access.
Write and read multiple device
parameters
Example:
• Read mass flow
• Reset totalizer
Broadcast messages are only allowed with function codes 06, 16 and 23.
9.3.2 Register information
For an overview of device parameters with their respective Modbus register
information, please refer to the "Modbus RS485 register information" section in the
"Description of device parameters" documentation → 210.
9.3.3 Response time
Response time of the measuring device to the request telegram of the Modbus master:
typically 3 to 5 ms
9.3.4 Modbus data map
Function of the Modbus data map
The device offers a special memory area, the Modbus data map (for a maximum of 16
device parameters), to allow users to call up multiple device parameters via Modbus RS485
and not only individual device parameters or a group of consecutive device parameters.
Grouping of device parameters is flexible and the Modbus master can read or write to the
entire data block simultaneously with a single request telegram.
Structure of the Modbus data map
The Modbus data map consists of two data sets:
• Scan list: Configuration area
The device parameters to be grouped are defined in a list in that their Modbus RS485
register addresses are entered in the list.
• Data area
The measuring device reads out the register addresses entered in the scan list cyclically
and writes the associated device data (values) to the data area.
For an overview of device parameters with their respective Modbus register
information, please refer to the "Modbus RS485 register information" section in the
"Description of device parameters" documentation → 210.
To Next Page
Loading...
