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Serial rlc protocol communications, Sending serial commands and data to the meter, Command chart – Red Lion PAX2A User Manual

Page 28: Command string construction, Register identification chart, Command string examples, Sending numeric data

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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 $.

Command Chart

COMMAND DESCRIPTION

NOTES

N

Node Address

Specifier

Address a specific meter. Must be followed by a

one or two digit node address. Not required when

address = 0.

T

Transmit Value

(read)

Read a register from the meter. Must be followed

by register ID character

V

Value Change

(write )

Write to register or output. 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

1 or 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 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 $. 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

Absolute Input

value

ABS

T

O

Offset

OFS

T, 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.

REGISTER

ADDRESS

REGISTER NAME

LOW LIMIT HIGH LIMIT

FACTORY

SETTING

ACCESS

COMMENTS

FACTORY SERVICE

40501-40506

Factory Service Registers

N/A

N/A

N/A

Read/Write Factory Use Only - Do Not Modify

41001-41010

Slave ID

N/A

N/A

N/A

Read Only

RLC-PAX2A <0100h><0020h><0020h><0010h

>

= SP Card Status. “0”-No Card, “2”-Dual SP,

“4”-Quad SP

= Linear Card Status. “0”-Not Installled,

“1”-Installed

<0100h> = Version Number (1.00 or higher)

<0020h><0020h> = 32 Register Writes, 32 Register

Reads (Max.)

<0010h> = 16 Register GUID/Scratch

41101-41116

GUID/Scratch

N/A

N/A

N/A

Read/Write Reserved (may be used in future RLC software)