Proline Promass F 100 Modbus RS485
System integration
47
Code
Name
Description
Application
03
Read holding
register
Master reads one or more Modbus
registers from the device.
A maximum of 125 consecutive
registers can be read with 1
telegram: 1 register = 2 bytes
The measuring device does
not make a distinction
between function codes 03
and 04; these codes therefore
yield the same result.
Read device parameters with read
and write access
Example:
Read mass flow
04
Read input
register
Master reads one or more Modbus
registers from the device.
A maximum of 125 consecutive
registers can be read with 1
telegram: 1 register = 2 bytes
The measuring device does
not make a distinction
between function codes 03
and 04; these codes therefore
yield the same result.
Read device parameters with read
access
Example:
Read totalizer value
06
Write single
registers
Master writes a new value to
one
Modbus register of the measuring
device.
Use function code 16 to write
multiple registers with just 1
telegram.
Write only 1 device parameter
Example: reset totalizer
08
Diagnostics
Master checks the communication
connection to the measuring device.
The following "Diagnostics codes"
are supported:
• Sub-function 00 = Return query
data (loopback test)
• Sub-function 02 = Return
diagnostics register
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 → 49
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.
