Manual

Trusted
TM
Communication Interface T8151B
Issue 21 Apr 10 PD-T8151B 33
If message control is required, select ‘Application Controls Message’ and enter the Modbus address of
an application variable that will be used to control the message. Where a control register is defined for
either a broadcast or slave message, the message is enabled when the register contains a zero value.
All other values will result in the message being disabled. The data type used for control variable can
be either boolean or integer but not real.
Variable Data Type Value Message
Boolean
False Enabled
True Disabled
Integer
0 Enabled
Non-zero Disabled
Table 12 Modbus Message Control Values
3.5.8. Statistics Tab
Figure 13 Modbus Slave Statistics Configuration
The statistical data records the time taken for a complete slave poll to be completed. The data is then
reported to the application using a defined Modbus data variable. The value returned is an integer
which represents the poll time in 1/100
th
second. There are three statistical values that may be
returned: the maximum scan time (‘Max Scan Rate’), the average scan time (‘Average’) or the latest
scan time (‘Scan Rate’). The statistics may be reset using the control variable.
To enable scan time statistics, select ‘Report Statistics’. Enter the Modbus address of an application
variable which will be used to send the data to the application in the ‘Data’ field. Select the Statistics
Type as appropriate.
Depending on the Statistics Type, the variable with the address defined in ‘Control’ has the function
described below. The variable may be Boolean or Integer. For Max Scan Rate and Average, a falling
and rising edge sequence will restart the measurement.