Red Lion LEGEND - Manual (Page 46)

SENDING COMMANDS AND DATA (Cont’d)
VALUE IDENTIFIERS MNEMONIC
A (41H) PRESET 1 P1
B (42H) PRESET 2 P2
C (43H) COUNT SCALE FACTOR SFC *
D (44H) RATE SCALE FACTOR SFR *
E (45H) COUNT CNT *
H (48H) RATE RAT *
I (49H) PEAK PEA *
J (4AH) VALLEY VAL *
K (4BH) PRESET 3 P3
L (4CH) PRESET 4 P4
M (4DH) PRESET 5 P5
N (4EH) PRESET 6 P6
O (4FH) COUNTER LOAD CLD
* From Factory Settings, the mnemonic transmitted is based on full mnemonic
programmed in Display Module. The print mnemonic is the first three
characters of the full mnemonic. The printed mnemonics for the Scale Factors
is SF followed by the first character of the full mnemonic for the value
associated with the Scale Factor.
Note: Command identifiers other than those listed should NOT be transmitted.
Otherwise, undefined or unpredictable operation could result.
The command string is constructed by using a command, a value identifier,
and a data value if required. The Data value need not contain the decimal
point since it is fixed within the Legend Plus unit, when programmed at the
front panel. The Legend Plus will accept the decimal point, however, it does
not interpret them in any way. Leading zeros can be eliminated, but all trailing
zeros must be present.
Example: If a Scale Factor of 1.0000 is to be sent, the data value can be
transmitted as 1.0000 or 10000. If a “1” is transmitted, the Scale Factor will
be changed to 0.0001.
The Address command is used to allow a command to be directed to a
specific unit on the Serial Communications Line. When the unit address is zero,
transmission of the Address command is not required. This is done for
applications that do not require more than one Legend Plus. For applications
that require several units, each Legend Plus on the line must be given a
non-zero address. If they are given the same address, a command such as the
Transmit Value Command, will cause all the units to respond simultaneously,
resulting in a communication collision. All Legend Plus units in a multiple unit
application should be given an address other than zero. If a unit has an address
of zero, it will attempt to process any transmissions from the other Legend Plus
units as commands. These transmissions fill up the receive buffer of the unit
with an address of zero, which may produce unpredictable results.
The command string is constructed in a specific logical sequence. The
Legend Plus does not accept command strings that do not follow this
sequence. Only one operation can be performed per command string. Below
is the procedure to be used when constructing a command string.
1. The first two or three characters of the command string must consist of the
Address Command (N) and the address number of the unit (1 to 99). If the
Legend Plus address is zero, the address command and number need NOT
be sent.
2. The next characters in the command string is the actual command that the
Legend Plus is to perform (M, MC, P, R, T, or V).
3. A Value or command Identifier is next if it pertains to the command. The
command P (print) does not require a Value Identifier.
4. The numerical data will be next in the command string if the “Change
Value” command is used.
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