It is recommended that a “Transmit Value” command follow a “Change
Value” Command. If this is done, the reception of the data can provide a timing
reference for sending another command and will ensure that the change has
occurred. When a “Change Value or Reset Value” command is sent to the C48T,
there is time required for the unit to process the command string. The diagrams
show the timing considerations that need to be made.
Receiving Data
Data is transmitted from the C48T when a “T” Transmit Value or a “P”
Transmit Print Options command is sent to the unit via the serial port or when
a User Input, programmed for the Print Request function, is activated. The
C48T will wait a minimum of 100 msec and then begin transmissions. The
C48T can also be programmed to transmit mnemonics. The format for a typical
transmission string with mnemonics is shown below:
The first two digits transmitted are the unit address followed by one blank
space. The next three characters are the mnemonics followed by three or more
blank spaces. The numerical data value is transmitted next. The decimal point
position will “float” within the data field depending on the actual value it
represents. The numeric data is right justified without leading zeros.
When a “T” command or print request is issued, the above character string is
sent for each line of a block transmission. An extra <SP><CR><LF> is
transmitted following the last line of transmission from a print request, to
provide separation between print outs.
If serial is abbreviated (
SErAbr
=
YES
), just numeric data is sent with no time
delay. If the C48T transmits mnemonics, there is a 400 msec built-in time delay
after each transmission string. When interfacing to a printer, sending
mnemonics is usually desirable. Examples of transmissions are shown below:
3 P2 6732.5<CR><LF> Mnemonics Sent
6732.5<CR><LF> NO Mnemonics Sent
The various Print Options are used with a printer or a Computer Terminal.
They provide a choice of which C48T data values are to be printed, when either
the User Input, programmed for the print request function is activated, or a “P”
(Transmit Print Options) command is sent to the C48T via the serial port. See
Print Options, page 21, for the available options.
Print outs from a C48T unit with an address of 1 and the following print
options are shown below:
-26-
Figure 14, Transmission String
PrnOPt
=
1
PrnOPt
=
2
PrnOPt
=
3
1 TMR
3.45.6
1 P1
3000
1 TMR
3.45.6
1 P2
6000
1 P1
3000
1 P2
6000
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