Siemens SITRANS FC410, Руководство по эксплуатации, Страница: 123 / 160

Modbus holding registers
A.2 Modbus function codes
FC410 with Modbus
Operating Instructions, 02/2016, A5E33120874-AC
121
Sub-
function
code
(Dec)
Name Description
12 Return Bus Communication
Error Count
The response data field returns the quantity of CRC errors
encountered by the remote device since its last restart,
clear counters execution, or power–up.
13 Return Bus Exception Error
Count
The response data field returns the quantity of MODBUS
exception responses returned by the remote device since
its last restart, clear counters execution, or power–up.
14 Return Slave Message
Count
The response data field returns the quantity of messages
broadcast or addressed to the remote device that the
remote device has processed since its last restart, clear
counters execution, or power–up.
15 Return Slave No Response
Count
The response data field returns the quantity of messages
addressed to the remote device for which it has returned no
response (neither a normal response nor an exception
response), since its last restart, clear counters execution, or
power–up.
16 Return Slave NAK Count The response data field returns the quantity of messages
addressed to the remote device for which it returned a
Negative Acknowledge (NAK) exception response, since its
last restart, clear counters execution, or power–up.
17 Return Slave Busy Count The response data field returns the quantity of messages
addressed to the remote device for which it returned a Sla-
ve Device Busy exception response, since its last
restart, clear counters execution, or power–up.
18 Return Bus Character
Overrun Count
The response data field returns the quantity of messages
addressed to the remote device that it could not handle due
to a character overrun condition, since its last restart, clear
counters execution, or power–up.
20 Clear Overrun Counter and
Flag
Clears the overrun error counter and resets the error flag.
Function code 8 example
Query
Slave address 1 byte
Function 1 byte
Sub-function Hi 1 byte
Sub-function Lo 1 byte
Data Hi 1 byte
Data Lo 1 byte
: :
Data Hi 1 byte
Data Lo 1 byte
CRC 2 bytes