PAXUSB datasheet(26/32 Pages) REDLION

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COUNTER C SLAVE COMMUNICATIONS

Counter C may be programmed for , to act as a serial slave display. By

doing this, the carriage return <CR> is added as a valid command terminator

character for all serial command strings. The <CR> as a terminator may be very

useful for standard serial commands, even if Counter C is never displayed or

sent a slave message. The $ terminator should not be used in the slave mode. If

numeric values are not to be saved to memory, then send the value as a literal

transmission with <CR> terminator.

The Counter C slave display is right aligned. It has a capacity of displaying

six characters. When less than six characters are received, blank spaces will be

placed in front of the characters. If more than six characters are sent, then only

the last six are displayed. The meter has a 192 character buffer for the slave

display. If more than 192 characters are sent, the additional characters are

discarded until a terminator is received. Counter C processes numeric and literal

transmissions differently.

Numeric Transmissions

When a string that does not begin with #, T, V, P or R is received, the meter

processes it as a Numeric transmission. In this case, only the recognized

numbers and punctuation are displayed. All other characters in the string are

discarded. If a negative sign appears anywhere in the string the resulting number

will be negative. Only the most significant decimal point is retained. If no

numerical characters are received, then the numeric value will be zero. The

numeric display can be used for setpoint (boundary action only) and analog

output functions. When using this display for setpoint and analog output values,

the decimal point position must match the programming entered through the

front panel. The numeric value is retained in Counter C memory until another

Numeric transmission is received.

Recognized Numbers = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Recognized Punctuation = period, comma, minus

Literal Transmissions

When a string that begins with # is received, the meter processes it as a Literal

transmission. In this case, any unrecognized characters will be replaced with a

space. A Literal display will replace a Numeric value in the Counter C display.

However, it will not remove a previous Numeric value from Counter C memory

or prevent the Counter C outputs from functioning with the Numeric value.

Literal transmissions are only possible when using RS232 or RS485 cards.

Recognized Characters = a, b, c, d, e, f, g, h, i, j, l, n, o, p, q, r, s, t, u,

y, z (in upper or lower case)

Recognized Numbers = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Recognized Punctuation = period, comma, minus, blank

RECEIVING DATA FROM THE METER

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. The

meter response mode is established in Module 7.

Full Field Transmission (Address, Mnemonic, Numeric data)

Byte

Description

1, 2

2 byte Node (meter) Address field [00-99]

<SP> (Space)

4-6

3 byte Register Mnemonic field

7-18

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

* 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, an *

(used as an overflow character) replaces the space in byte 7. 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 <CR> (byte 19), and <LF>

(byte 20). When a block print is finished, an extra <SP> (byte 21), <CR> (byte

22), and <LF> (byte 23) are used to provide separation between the transmissions.

Abbreviated Transmission (Numeric data only)

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

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

Meter Response Examples:

1. Address = 17, full field response, Count A = 875

17 CTA 875 <CR><LF>

2. Address = 0, full field response, Setpoint 2 = -250.5

SP2 -250.5<CR><LF>

3. Address = 0, abbreviated response, Setpoint 2 = 250, last line of block print

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

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:

Value

Output Signal*

0-20 mA 4-20 mA

0-10 V

0.00

4.00

0.000

0.005 4.004

0.0025

2047

10.000 12.000

5.000

4094

19.995 19.996 9.9975

4095

20.000 20.000 10.000

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

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.

*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).

PAXUSB Datasheet(PDF) 26 Page - Red Lion Controls. Inc

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