CBLUSB01 datasheet(26/36 Pages) REDLION

26 / 36 page

Sending Commands and Data

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 the command terminator character * or $.

Command Chart

Command Description

Notes

Node Address

Specifier

Address a specific meter. Must be followed by

one or two digit node address. Not required

when node address = 0.

Transmit Value (read) Read a register from the meter. Must be

followed by register ID character.

Value change (write)

Write to register of the meter. Must be

followed by register ID character and numeric

data.

Reset

Reset a register or output. Must be followed

by register ID character

Block Print Request

(read)

Initiates a block print output. Registers are

defined in programming.

ID Value Description

Applicable Commands/Comments

A Input

INP

(Reset command [Ver2.5+]

zeros the input [“REL” or Tare])

B Total

TOT

(Reset command resets total to

zero)

C Max Input

MAX

(Reset command resets MAX to

current reading)

D Min Input

MIN

(Reset command resets MIN to

current reading)

E Setpoint 1

SP1

(Reset command resets the

setpoint output)

F Setpoint 2

SP2

(Reset command resets the

setpoint output)

G Setpoint 3

SP3

(Reset command resets the

setpoint output)

H Setpoint 4

SP4

(Reset command resets the

setpoint output)

I Analog Output

AOR

(Applies to manual mode)

Offset/Tare (PAXS)

Absolute (gross)

input display value

Control Status

OFS

TAR †

ABS

GRS †

CSR

(Ver 2.5+)

T, P, R

T, P, V, R

T, V

T, P, V

T, P

T, V

Command String Construction

The command string must be constructed in a specific sequence. The meter

does not respond with an error message to illegal commands. The following

procedure details construction of a command string:

1. The first 2 or 3 characters consist of the Node Address Specifier (N) followed

by a 1 or 2 character node address number. The node 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 $. The meter does not begin processing the command string

until this character is received. See timing diagram figure for differences of *

and $ terminating characters.

Command String Examples:

1. Node address = 17, Write 350 to Setpoint 1, response delay of 2 msec min

String: N17VE350$

2. Node address = 5, Read Input value, response delay of 50 msec min

String: N5TA*

3. Node address = 0, Reset Setpoint 4 output, response delay of 50 msec min

String: RH*

Sending Numeric Data

Numeric data sent to the meter must be limited to 5 digits (-19,999 to 99,999).

If more than 5 digits are sent, the meter accepts the last 5. 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 In this case, write a value = 25.0).

Note: Since the meter does not issue a reply to value change commands, follow

with a transmit value command for readback verification.

Receiving Data

Data is transmitted by 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. In this

case, the response contains only the numeric field. The meter response mode is

established in programming.

Full Field Transmission

* These characters only appear in the last line of a block print.

The first two characters transmitted are the node address, unless the node address

assigned =0, in which case spaces are substituted. A space follows the node address

field. The next three characters are the register ID (Serial Mnemonic).

The numeric data is transmitted next. The numeric field is 12 characters long

(to accommodate the 10 digit totalizer), with the decimal point position floating

within the data field. Negative value have a leading minus sign. The data field

is right justified with leading spaces.

The end of the response string is terminated with a carriage return <CR> and

<LF>. When block print is finished, an extra <SP><CR> <LF> is used to

provide separation between the blocks.

Abbreviated Transmission

* These characters only appear in the last line of a block print.

The abbreviated response suppresses the node address and register ID,

leaving only the numeric part of the response.

Meter Response Examples:

1. Node address = 17, full field response, Input = 875

17 INP

875 <CR><LF>

2. Node address = 0, full field response, Setpoint 2 = -250.5

SP2

-250.5<CR><LF>

3. Node address = 0, abbreviated response, Setpoint 2 = 250, last line of block

250<CR><LF><SP><CR><LF>

Byte

Description

1, 2

2 byte Node Address field [00-99]

<SP> (Space)

4-6

3 byte Register Mnemonic field

7-18

<CR> carriage return

<LF> line feed

<SP>* (Space)

<CR>* carriage return

<LF>* line feed

Byte

Description

1-12 12 byte data field, 10 bytes for number, one byte for sign,

one byte for decimal point

<CR> carriage return

<LF> line feed

<SP>* (Space)

<CR>* carriage return

<LF>* line feed

12 byte data field; 10 bytes for number, one byte for sign, one byte for

decimal point (The T command may be a different byte length)

† -Register ID for the PAXS.

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