User Manual

Commissioning
SmartRadar FlexLine Part No.: 4417.762_Rev07
6 - 32 Service Manual
6.3.3.7 Modbus Coils
The following table lists Modbus commands and their related addresses
(coils) and data.
NOTE: Coils are just names for memory addresses. The
other way to look at it is that they are just pre-defined
variable names. A coil is a boolean (bit) variable, and
a register is an integer (word) variable.
6.3.3.8 Modbus Exception Handling
When a Modbus master device sends a request to a FlexLine device, it
expects a normal response. One of four possible events can occur from
the master’s query:
 If the FlexLine device receives the request without a communication
error, and can handle the query normally, it returns a normal
response.
 If the FlexLine device does not receive the request due to a commu-
nication error, no response is returned. The master program will
eventually process a timeout condition for the request. Typically 2
retries are carried out before going into fail.
 If the FlexLine device receives the request, but detects a communi-
cation error (parity, LRC, CRC), no response is returned. The master
program will eventually process a timeout condition for the request.
 If the FlexLine device receives the request without a communication
error, but cannot handle it (for example, if the request is to read a
non–existent output or register), the FlexLine device will return an
exception response informing the master of the nature of the error.
The exception-response message has two fields that differentiate it
from a normal response:
 Function code field:
In a normal response, the FlexLine device echoes the function code
Modbus command
Modbus
address (hex)
Modbus
address (dec)
Data
Number of
registers
FlexConn Modbus Protocol Switch 0x00 00001 0xFF00 1
Reset Device 0x10 00017 0xFF00 1
Product Level Alarm Test Hi Hi 0x11 00018 0xFF00 1
Product Level Alarm Test Hi 0x12 00019 0xFF00 1
Product Level Alarm Test Lo 0x13 00020 0xFF00 1
Product Level Alarm Test Lo Lo 0x14 00021 0xFF00 1
Start Proof Test First Relay Board 0x15 00022 0xFF00 1
Stop Proof Test First Relay Board 0x16 00023 0xFF00 1
Start Proof Test Second Relay Board 0x17 00024 0xFF00 1
Stop Proof Test Second Relay Board 0x18 00025 0xFF00 1