Rockwell Automation T8xxx Trusted Communications Interface - Manual (Page 27)

Trusted
TM
Communication Interface T8151B
Issue 21 Apr 10 PD-T8151B 27
There are three modes of operation.
One Shot: In this mode a single broadcast sequence is sent when an edge is detected on the control
variable within the application. Once all enabled broadcast messages have been sent, the mode will be
suspended until a new edge is seen on the control variable.
Message Count: The broadcast sequence is sent after a fixed number of slave messages have been
sent. The number of messages is set in the configuration (‘Every xxx messages’) and cannot be
changed by the application at run time. All messages sent to the slaves are counted. Note that
messages which have been configured but are disabled by the application will not be counted as sent
messages. Once the required number of slave messages has been sent, the broadcast sequence will
commence. The control variable may be configured to enable and disable the broadcast mode if
required.
Fixed Time: The broadcast sequence is sent at a fixed time interval defined in the configuration. The
time interval is set in the configuration (‘Every xxx msec’) and cannot be changed by the application at
run time. The time interval measurement is taken from the point of sending the first broadcast
message and ignores the time taken to send the sequence and any wait times. Therefore the time
interval must be set to a value greater then the time taken to send the broadcast sequence. The
control variable may be configured to enable and disable the broadcast mode if required.
When a broadcast is initiated, all enabled messages in the list are sent one after another. The time
interval between each message can be configured to allow for the processing time of the slave devices
(using ‘Wait Time’).
The slave message scheduling can be configured using ‘Slave List Control’ to restart with the first
defined message for each slave after the broadcast sequence has completed (‘Restart’), or suspend
the sequence and continue at the same point after the broadcast (‘Suspend’).
To create a broadcast message, click ‘New’.
Figure 8 Broadcast Message Configuration
The Message Configuration window is the same as that used for messages to specific slaves.
Select a Message Type from the list. For broadcast messages, only Write Coils (multiple Boolean
variables) and Write Registers (multiple analogue variables) messages are allowed.
The Variable Network Address is the Modbus address range of the variables as mapped in the
Trusted
TM system. Only the starting address is needed; the end address is calculated automatically.
The Modbus Slave Address is the slave’s address range for the variables. Enter the start and end
addresses. Coils are addressed from 1 to 9999 and registers are mapped from 40001 to 49999. Up to
512 coils or 123 registers may be written in a single message.