Red Lion PAX2S - Manual (Page 25)

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SERIAL RLC PROTOCOL COMMUNICATIONS
RLC Communications requires the Serial Communications Type Parameter
(tYPE) be set to “rLC”.
SENDING SERIAL COMMANDS AND DATA TO THE METER
When sending commands to the meter, a string containing at least one
command character must be constructed. A command string consists of a
command character, a value identifier, numerical data (if writing data to the
meter) followed by a command terminator character * or $. The is also
available as a terminator when Counter C is in the SLAVE mode.
Command Chart
COMMAND DESCRIPTION NOTES
N Node (Meter)
Address
Specifier
Address a specific meter. Must be followed by a
two digit node address. Not required when
address = 00.
T Transmit Value
(read)
Read a register from the meter. Must be followed
by register ID character
V Value Change
(write)
Write to register of the meter. Must be followed by
register ID character and numeric data.
R Reset Reset a register or output. Must be followed by
register ID character.
P Block Print
Request
Initiates a block print output. Registers are defined
in programming.
Command String Construction
The command string must be constructed in a specific sequence. The meter
does not respond with an error message to invalid commands. The following
procedure details construction of a command string:
1. The first characters consist of the Node Address Specifier (N) followed by a
2 character address number. The address number of the meter is programmable.
If the node address is 0, this command and the node address itself may be
omitted. This is the only command that may be used in conjunction with other
commands.
2. After the optional address specifier, the next character is the command
character.
3. The next character is the Register ID. This identifies the register that the
command affects. The P command does not require a Register ID character.
It prints according to the selections made in print options.
4. If constructing a value change command (writing data), the numeric data is
sent next.
5. All command strings must be terminated with the string termination
characters *, $ or when Counter C is set for slave mode . The meter
does not begin processing the command string until this character is received.
See Timing Diagram figure for differences between terminating characters.
Register Identification Chart
ID VALUE DESCRIPTION MNEMONIC APPLICABLE COMMANDS/COMMENTS
A Input (relative
value)
INP T, P, R (Reset command resets input
to zero; tares)
B Total TOT T, P, R (Reset command resets total
to zero)
C Max Input MAX T, P, R (Reset command resets Max
to current reading)
D Min Input MIN T, P, R (Reset command resets Min
to current reading)
E Setpoint 1 SP1 T, P, V, R (Reset command resets
the setpoint output)
F Setpoint 2 SP2
G Setpoint 3 SP3
H Setpoint 4 SP4
I Band/Deviation 1 BD1 T, V
J Band/Deviation 2 BD2 T, V
K Band/Deviation 3 BD3 T, V
L Band/Deviation 4 BD4 T, V
M Gross (Absolute)
Input value
GRS T, P
O Tare (Offset) Value TAR T, P, R, V
U Auto/Manual
Register
MMR T, V
W Analog Output
Register
AOR T, V
X Setpoint Register SOR T, V
Command String Examples:
1. Node address = 17, Write 350 to Setpoint 1.
String: N17VE350$
2. Node address = 5, Read Input value.
String: N5TA*
3. Node address = 0, Reset Setpoint 4 output.
String: RH*
Sending Numeric Data
Numeric data sent to the meter must be limited to 6 digits (-199999 to
999999). Leading zeros are ignored. Negative numbers must have a minus sign.
The meter ignores any decimal point and conforms the number to the scaled
resolution. (For example: the meter’s scaled decimal point position = 0.0 and 25
is written to a register. The value of the register is now 2.5.
Note: Since the meter does not issue a reply to value change commands, follow
with a transmit value command for readback verification.