Modbus Keywords
You can use Modbus keywords alone or in combination with other
keywords such as
content and
byte_jump.
modbus_data
You can use the
modbus_data keyword to point to the beginning of the
Data field in a Modbus request or response.
modbus_func
You can use the
modbus_func keyword to match against the Function Code
field in a Modbus application layer request or response header. You can specify
either a single defined decimal value or a single defined string for a Modbus
function code.
The following table lists the defined values and strings recognized by the system for Modbus function codes.
|
Value |
String |
|---|---|
|
1 |
read_coils |
|
2 |
read_discrete_inputs |
|
3 |
read_holding_registers |
|
4 |
read_input_registers |
|
5 |
write_single_coil |
|
6 |
write_single_register |
|
7 |
read_exception_status |
|
8 |
diagnostics |
|
11 |
get_comm_event_counter |
|
12 |
get_comm_event_log |
|
15 |
write_multiple_coils |
|
16 |
write_multiple_registers |
|
17 |
report_slave_id |
|
20 |
read_file_record |
|
21 |
write_file_record |
|
22 |
mask_write_register |
|
23 |
read_write_multiple_registers |
|
24 |
read_fifo_queue |
|
43 |
encapsulated_interface_transport |
modbus_unit
You can use the
modbus_unit keyword to match a single decimal value
against the Unit ID field in a Modbus request or response header.