Auto/manual mode register (mmr) id: u – Red Lion PAXDP User Manual
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Transmitting Data From the Meter
Data is transmitted from the meter in response to either a transmit command
(T), a print block command (P) or User Function print request. The response
from the meter is either a full field transmission or an abbreviated transmission.
See Abbreviated Printing (
) parameter.
Full Transmission
These characters only appear in the last line of a block print.
The first two characters transmitted (bytes 1 and 2) are the unit address. If the
address assigned is 00, two spaces are substituted. A space (byte 3) follows the
unit address field. The next three characters (bytes 4 to 6) are the register
mnemonic. The numeric data is transmitted next.
The numeric field (bytes 7 to 18) is 12 characters long. When the requested
value exceeds eight digits for count values or five digits for rate values. Byte 8
is always a space. The remaining ten positions of this field (bytes 9 to 18)
consist of a minus sign (for negative values), a floating decimal point (if
applicable), and eight positions for the requested value. The data within bytes 9
to 18 is right-aligned with leading spaces for any unfilled positions.
The end of the response string is terminated with
(byte 20). When a block print is finished, an extra
22), and
Abbreviated Transmission
These characters only appear in the last line of a block print.
The abbreviated response suppresses the address and register mnemonics,
leaving only the numeric part of the response.
Meter Response Examples:
1. Address = 17, full field response, Input A = 875
17 INA 875
2. Address = 0, full field response, Setpoint 2 = -250.5
SP2 -250.5
3. Address = 0, abbreviated response, Setpoint 2 = 250, last line of block print
250
Auto/Manual Mode Register (MMR) ID: U
This register sets the controlling mode for the outputs. In Auto Mode (0) the
meter controls the setpoint and analog output. In Manual Mode (1) the outputs
are defined by the registers SOR and AOR. When transferring from auto mode
to manual mode, the meter holds the last output value (until the register is
changed by a write). Each output may be independently changed to auto or
manual. In a write command string (VU), any character besides 0 or 1 in a field
will not change the corresponding output mode.
U abcde
e = Analog Output
d = SP4
c = SP3
b = SP2
a = SP1
Example: VU00011 places SP4 and Analog in manual.
Analog Output Register (AOR) ID: W
This register stores the present signal value of the analog output. The range
of values of this register is 0 to 4095, which corresponds to the analog output
range per the following chart:
*Due to the absolute
accuracy rating and
resolution of the output
card, the actual output
signal may differ 0.15%
FS from the table values.
The output signal
corresponds to the range
selected (0-20 mA, 4-20
mA or 0-10 V).
Writing to this register (VW) while the analog output is in the Manual Mode
causes the output signal level to update immediately to the value sent. While in
the Automatic Mode, this register may be written to, but it has no effect until the
analog output is placed in the manual mode. When in the Automatic Mode, the
meter controls the analog output signal level. Reading from this register (TW)
will show the present value of the analog output signal.
Example: VW2047 will result in an output of 10.000 mA, 12.000 mA or
5.000V depending on the range selected.
Setpoint Output Register (SOR) ID: X
This register stores the states of the setpoint outputs. Reading from this
register (TX) will show the present state of all the setpoint outputs. A “0” in the
setpoint location means the output is off and a “1” means the output is on.
X abcd
d = SP4
c = SP3
b = SP2
a = SP1
In Automatic Mode, the meter controls the setpoint output state. In Manual
Mode, writing to this register (VX) will change the output state. Sending any
character besides 0 or 1 in a field or if the corresponding output was not first in
manual mode, the corresponding output value will not change. (It is not
necessary to send least significant 0s.)
Example: VX10 will result in output 1 on and output 2 off.
Byte
Description
1-12 12 byte data field, 10 bytes for number, one byte for sign, one byte
for decimal point
13
14
15
16
17
23
22
21
20
3 byte Register Mnemonic field
4-6
3
12 byte numeric data field: 10 bytes for number, one byte for sign, one
byte for decimal point
7-18
2 byte Node (Meter) Address field [00-99]
1, 2
19
Description
Byte
10.000
20.000
9.9975
19.996
5.000
12.000
0.0025
4.004
0.000
4.000
0-10V
4-20 mA
20.000
4095
19.995
4094
10.000
2047
Output Signal*
Register Value
0.005
1
0.000
0
0-20 mA