Table of Contents
Advertisement
4.2.
Modbus Protocol Parameter Descriptions
MDC-211-ZT is a Modbus data concentrator with Zigbee / RS-232 / RS-485 / Ethernet
interfaces. The users need to set a communication interface to Modbus Master / Modbus
Slave (The interface not used can be set to "Disabled"). The following sections describe the
parameters for setting to Modbus Master and Modbus Slave.
4.2.1. Modbus Master Setting Parameters
Parameter Description
Table 4.5 shows the descriptions for the Modbus Master setting parameters and the
setting notes.
Table 4.5 Modbus Master related parameter descriptions
Item
Description
Modbus
Polling
Timeout
Timeout
Number of
Modbus
polling
Retry
Retries
Polling
Polling
Interval
Interval
Note
It is the maximum time for waiting the response from Modbus
RTU device. If there is no response after the time expires, it is
considered as timeout and execute the next command.
Users can change the value as needed.
When the number of command timeouts exceeds the number
of retries, the MDC-211-ZT regards the Modbus RTU device as
offline and performs the following two operations:
a. Suspend this polling command for 10 seconds until the
device is back online again
b. The status of the Modbus command can be read via the
Internal Register of MDC-211-ZT, where the Register value of
0xFFFF is represented the timeout. (For more information can
see Chapter 5. FAQ-Q5)
The default of Modbus Retry is 3 times, users can change the
value as needed
The interval time for command polling to avoid communication
signal collisions.
Users can change the value as needed
ICP DAS, MDC-211-ZT user manual , v1.0
Copyright © 2018 by ICP DAS. All rights are reserved.
Page 36
Advertisement
Table of Contents
