58 Pelco Manual C573M-D (11/03)• Optional command parameters depend on the function byte ([00] to [09]) and include
the following:
– [Channel] = [00] to [15] in packed BCD format, which defines the channel number
of the MDA unit
–[Row] = [01] to [05] in packed BCD format, which defines the row number in
which message text is to be set or cleared
–[Message Text] = specifies the message text to be displayed:
•1 to 24 characters for one line of message text
•4 to 124 characters, where:
Minimum = 4 message separator bytes ([7F][7F][7F][7F]) and no message
text
Maximum = 124 bytes: 5 messages containing 24 characters each (120
message bytes) plus 4 message separator bytes ([7F][7F][7F][7F])
– [Format] = [00] or [01], where:
[00] = displays message text below the title/time/date text
[01] = displays message text above the title/time/date text
– [Row-Separation] = [00] to [28], which defines the number of blank rows
separating the title/time/date text and the message text displays
–[Rows-to-Display/Scroll] = [00] to [05], which defines the number of message text
lines to be displayed. Also defines the number of message text lines to be
scrolled.
–[High Message Time][Low Message Time] = Message time bytes that are
transmitted and received in packed BCD format. The message time bytes define
the number of seconds that the message text is to be displayed. The maximum
display time-out is 9,999 seconds. A display time-out of 0 seconds allows the text
to be displayed indefinitely or until overwritten.
•Last two bytes of each command are as follows:
[AF][Checksum]
where:
–[AF] = signals end of the command
–[Checksum] = exclusive-or of all other bytes in the command