FEC920: USER GUIDE
Page 91
September 18
6.6.1 Slave Main menu
This allows the IP address, Unit ID and other communications parameters to be entered for Slaves 1 and 2.
Figure 81 Modbus Master Slave 1 configuration (Slave 2 similar)
Descriptor
A descriptor for this instrument. For use in Modbus communications, this is not the same
as the ‘Name’ which appears in the Instrument Info configuration (Section 6.12).
Online
Disabled by default (Cross symbol). Must be enabled (highlighted using the down arrow,
then edited by the scroll button) to allow the remaining configuration items to appear and
to allow data transactions be processed. Setting the slave offline temporarily disables data
transactions - it does not reconfigure them.
Comms Failure
Active (yes) if a data item has failed to respond after all retries.
IP Address
The IP address of the Slave device.
Unit ID
The Unit Id or Modbus address to use in each data transaction with the slave device.
Limits are 1 to 255.
Search Device
Setting this to ‘Yes’ searches the network to see if the device with the specified IP address
and Unit ID is available. If so, the descriptor will be overwritten to indicate what type of
device has been found.
Search Result
The status of the selected 'Search Device' request (Searching, Available, Unreachable).
Search activity is indicated by a rotating animated display in the ‘Searching’ field.
Profile
A number of profiles are held within the instrument that match a selection of known
devices. If the device is ‘known’, its type, model number etc. is displayed. If the device is
unknown, ‘3rd Party’ appears instead.
Retries
The number of times (0 to 3) to re-send a data transaction to the device if no response is
received within the configured timeout period (below).
Timeout
The timeout period for each Modbus transaction in ms.
Max Block Size
The maximum number of registers (16bit words) that a single data transaction is permitted
to contain.
High Priority
The interval rate between each high priority data transaction. Default = 0.125 second.
Medium Priority
The interval rate between each medium priority data transaction. Default = 1 second.
Low Priority
The interval rate between each low priority data transaction. Default = 2 seconds.
FEC920
No
123.123.123.111
1
No
Available
Descriptor
Online
Comms Failure
IP Address
Unit ID
Search Device
Search Result
Modbus Master.Slave.1.Main
Profile
Retries
Timeout (ms)
Max Block Size
High Priority
Medium Priority
Low Priority
FEC920
3
250
124
0.125 sec
1 sec
2 secs
Seconds
0.125
0.25
0.5
1
2
5
10
20
30
Minutes
1
2
5
10
20
30
Hours
1
Available Priority selections
A5E45696052A Rev-AA
