Abrv, Serial communications, Serial modbus communications – Red Lion PAX2S User Manual

Page 23: Supported function codes, Supported exception codes

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23

USB

The USB programming port is primarily intended to be used to configure the

PAX2S with the Crimson programming software. It can also be used as a virtual

serial communications port following installation of the PAX2S USB drivers

that are supplied with the Crimson software. When the USB port is being used,

i.e. the USB cable is connected between PAX2S and PC, all serial communications

with the serial option card (if used) is disabled.

USB Cable type required: USB A to Mini-B (not supplied)

PAX2S CONFIGURATION USING CRIMSON AND USB

1. Install Crimson software.

2. Supply power to PAX2S

3. Insure USB Configuration “CONFIG” in USB Port Parameters is set to

“AUtO” (factory default setting).

4. Attach USB cable (USB A to Mini-B) between PC and PAX2S.

5. Create a new file (File, New) or open an existing PAX2S database within

Crimson.

6. Configure Crimson Link options (Link, Options) to the serial port which the

USB cable is attached (in Step 4).

SERIAL MODBUS COMMUNICATIONS

Modbus Communications requires that the Serial Communication Type

Parameter (tYPE) be set to “Mbrtu” or “MbASC”.

PAX2S CONFIGURATION USING CRIMSON AND SERIAL

COMMUNICATIONS CARD

1. Install Crimson software.

2. Install RS232 or RS485 card and connect communications cable from PAX2S

to PC.

3. Supply power to PAX2S

4. Configure serial parameters (SERIAL) to Modbus RTU “Mbrtu”, 38,400 baud,

address 247.

5. Create a new file (File, New) or open an existing PAX2S database within

Crimson.

6. Configure Crimson Link options (Link, Options) to the serial port which the

communication cable is attached (in step 2).

SUPPORTED FUNCTION CODES

FC03: Read Holding Registers

1. Up to 64 registers can be requested at one time.

2. HEX <8000> is returned for non-used registers.

FC04: Read Input Registers

1. Up to 64 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.

FC16: Preset Multiple Registers

1. No response is given with an attempt to write to more than 64 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.

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 PAX2. “Total Good Comms” is the total messages received by the

PAX2S with good address, parity and checksum. Both counters are reset to

0 upon response to FC08 and at power-up.

FC17: Report Slave ID

The following is sent upon FC17 request:

RLC-PAX2S ab<0100h><40h><40h><10h>

a = SP Card, “0”-No SP, “2” or “4” SP

b = Linear Card “0” = None, “1” = Yes

<0100> Software Version Number (1.00)

<40h>Max Register Reads (64)

<40h>Max Register Writes (64)

<10h> Number Guid/Scratch Pad Regs (16)

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.

serial COmmuniCaTiOns

The PAX2S supports serial communications using the optional serial communication cards or via the USB programming port located on the side of the unit. When

USB is being used (connected), the serial communication card is disabled. When using the standard RS232 and RS485 Pax option cards, the PAX2S supports both the

RLC protocol and also supports Modbus communications. The PAX Modbus option card should not be used with the PAX2S, as the PAX2S internal Modbus protocol

supports complete unit configuration, and is much more responsive.

The following programming steps are only available when Communications Type
(

tYPE

) is programmed for

rLC

.

ABBREVIATED PRINTING

NO YES

Select YES for full print or Command T transmissions (meter address,

mnemonics and parameter data) or NO 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

NO YES

YES

- Enters the sub-menu to select the meter parameters to appear during a print

request. For each parameter in the sub-menu, select YES for that parameter

information to be sent during a print request or NO 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, mnemonics

and parameter data) can be sent to a printer or computer as a block.

DISPLAY

DESCRIPTION

FACTORY

SETTING

MNEMONIC

INPUt

Signal Input

YES

INP

GrOSS

Gross (absolute) Value

NO

GRS

tArE

Tare Value

NO

TAR

tOtAL

Total Value

NO

TOT

HILO

Max & Min

NO

MAX, MIN

SPNt

Setpoint Values

NO

SP1-SP4

Abrv

NO

SRL

OPt

NO

SRL

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