Serial modbus communications, Supported function codes, Supported exception codes – Red Lion PAXDP User Manual
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TRANSMIT DELAY
CRIMSON SOFTWARE
Following a transmit value (‘*’ terminator) or Modbus command, the
PAXDP will wait this minimum amount of time in seconds before issuing a
serial response.
to
When communicating with Crimson 2 software, the PAXDP must be set in
default configuration type of:
Communications Type: MODBUS RTU
†
Baud Rate: 38400
Data Bit: 8
ParityBit: no
Meter Unit Address: 247
SERIAL MODBUS COMMUNICATIONS
Modbus Communications requires that the Serial Communication Type
Parameter (
) be set to “
” or “
”.
SUPPORTED FUNCTION CODES
FC03: Read Holding Registers
1. Up to 32 registers can be requested at one time.
2. HEX <8000> is returned for non-used registers.
FC04: Read Input Registers
1. Up to 32 registers can be requested at one time.
2. Block starting point can not exceed register boundaries.
3. HEX <8000> is returned in registers beyond the boundaries.
4. Input registers are a mirror of Holding registers.
FC06: Preset Single Register
1. HEX <8001> is echoed back when attempting to write to a read only
register.
2. If the write value exceeds the register limit (see Register Table), then that
register value changes to its high or low limit. It is also returned in the
response.
FC08: Diagnostics
The following is sent upon FC08 request:
Module Address, 08 (FC code), 04 (byte count), “Total Comms” 2 byte count,
“Total Good Comms” 2 byte count, checksum of the string
“Total Comms” is the total number of messages received that were addressed
to the PAXDP. “Total Good Comms” is the total messages received by the
PAXDP with good address, parity and checksum. Both counters are reset to 0
upon response to FC08 and at power-up.
FC16: Preset Multiple Registers
1. No response is given with an attempt to write to more than 32 registers at
a time.
2. Block starting point cannot exceed the read and write boundaries (40001-
41280).
3. If a multiple write includes read only registers, then only the write registers
will change.
4. If the write value exceeds the register limit (see Register Table), then that
register value changes to its high or low limit.
FC17: Report Slave ID
The following is sent upon FC17 request:
RLC-PAXDP ab<0100h><20h><20h><10h>
16 Guid/Scratch Pad
Max Register Reads (32)
Max Register Writes (32)
Software Version Number
b = Linear Card “0” = None, “1” = Yes
a = SP Card, “0”-No SP, “2” or “4” SP
a = “0”(none), “2”, “4” SP card installed
b = “0”(none) or “1” Linear Card installed),
SUPPORTED EXCEPTION CODES
01: Illegal Function
Issued whenever the requested function is not implemented in the meter.
02: Illegal Data Address
Issued whenever an attempt is made to access a single register that does not
exist (outside the implemented space) or to access a block of registers that falls
completely outside the implemented space.
03: Illegal Data Value
Issued when an attempt is made to read or write more registers than the meter
can handle in one request.
07: Negative Acknowledge
Issued when a write to a register is attempted with an invalid string length.
21
ABBREVIATED PRINTING
Select
for full print or Command T transmissions (meter address,
parameter data and mnemonics) or
for abbreviated print transmissions
(parameter data only). This will affect all the parameters selected in the print
options. (If the meter address is 00, it will not be sent during a full transmission.)
PRINT OPTIONS
- Enters the sub-menu to select the meter parameters to appear during a
print request. For each parameter in the sub-menu, select
for that parameter
information to be sent during a print request or
for that parameter information
not to be sent. A print request is sometimes referred to as a block print because
more than one parameter information (meter address, parameter data and
mnemonics) can be sent to a printer or computer as a block.
PARAMETER
DESCRIPTION
Input A Value
Input B Value
Calculation
Total Value
Max. & Min.
Setpoint Values
Parameters below only appear when communications type (
) parameter
is set to
.