Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL - Manual (Page 88)

Parallel Port Communications 7–8
Publication 2706-6.1
Override Slave Address Selected as a Message Attribute
The Message/Variable/Slave Run mode allows runtime override of
the slave address specified in the “Send to Slave” message attribute.
To send a message to a slave, Port Use of the RS-485 or RS–232 Port
must be set to DL Slaves.
Triggering Rules
•
Optional slave address must always precede the message number.
•
Up to 10 variables are addressable within a message.
•
Variables must always follow the message number.
•
Variables are always associated with the last message triggered:
– if the message is in the queue, variables are put into the queue
(with the message) and onto the Historical Events Stack.
– if the message is running and the variable is displayed, the
variable is updated with the latest data and the data is put onto
the Historical Events Stack.
– if the message is running and the variable is no longer shown
(as in a scrolling message), new data is not shown but is put
on the Historical Events Stack.
– if the message is finished running, new data is lost to the
display and to the Historical Events Stack.
•
BCD Sign Bit – Only valid for [CTRL][V] BCD variables; not
valid for [CTRL][W ] BCD.
– Set = –
– Clear
= +
– Sign bits must precede variables. The sign cannot be changed
without resending the variable.
– Bit 0 = Variable l
– Bit 1 = Variable 2, etc.
– Bits 9 through 15 ignored
– No Sign Bit sent (default) = +
Note: For BCD variables only. Ignored for binary and ASCII
variables. To sign a binary variable, use 2’s complement.