Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL User Manual

Page 88

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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.

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