Red Lion LEGEND - Manual (Page 47)

5. All command strings must be terminated with an asterisk* (2AH). This
character indicates to the Legend Plus that the command string is complete
and begins processing the command Below are some typical examples of
properly constructed command strings.
(EX. 1) Change Preset 1 Value to 123.4 on the Legend Plus with an
address of 2.
COMMAND STRING: N2VA1234*
(EX. 2) Transmit the Count Value of the Legend Plus unit with an
address of 3.
COMMAND STRING: N3TE*
(EX. 3) Reset Output 1 of the Legend Plus unit with an address of 0.
COMMAND STRING: R1*
If illegal commands or characters are sent to the Legend Plus, the unit
addressed responds by transmitting an error character “E” (45H) in which
case the string must be re-transmitted.
When writing application programs in Basic, the transmission of spaces or
carriage return and line feed should be inhibited by using the semicolon
delimiter with the “PRINT” statement. The Legend Plus will not accept a
carriage return or line feed as valid characters. See “Terminal Emulation
Program” section for a listing of an IBM
®
PC Basic terminal emulation program.
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 ensures that the change
has occurred. When a “Change Value or Reset Value” command is sent to the
Legend Plus, time is required for the unit to process the command string. The
diagrams show the timing considerations that need to be made. The Legend
Plus process times shown are for a Legend Plus operating at the maximum
count rate. The process times are count rate dependent and will be
considerably less when the unit is operating at low count rates.
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