Serial rtc master addressing, Sending serial commands and data – Red Lion PAXCK User Manual

Page 21

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SERIAL RTC MASTER ADDRESSING

A meter, having software code version 2.3 or greater, with a Real Time Clock

Card and an RS485 Serial Communication Card installed, can act as a Serial
RTC Master, when programmed with meter address 98 or 99. With this feature,
whenever the Master meter's time, date or day is changed, through quick or
main programming, it will transmit and make the same change to the other
PAXCK's on the RS485 bus. Only one meter should be configured as Master.
This Master, with address 98 or 99, should also be programmed as the “Host”
in module

SUD

under Clock Synchronization. With it programmed as Host,

the other PAXCK Slaves will update hours, minutes and seconds to the Host
once an hour and the Real-Time Clock Wiring (terminals 16-18) will not be
necessary.

Meter addresses 98 and 99 are distinguished as follows:With address 98, the

meter will transmit the change to all meters on the RS485 bus addressed as “0”.
This is useful when using both newer or older software code version meters, or
when another master (computer, operator interface) is not being used.

With address 99, the meter will transmit the change to all, software code

version 2.3 or greater, meters on the RS485 bus using a global broadcast address
suffix. This is useful when it is necessary to have unique or other than 0 serial
meter addresses or when having a computer or operator interface connected.

SENDING SERIAL 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 the command terminator character * or $.

Command Chart

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. The address suffix , “?” is the global broadcast address
specifier. A command string that is sent with N? prefix will be accepted by
all PAXCKs on the RS485 network (software code version 2.3 or greater).
This is useful for setting all meters to the current time, date or day that may
have unique meter addresses on a bus. It is important not to send (P)rint or
(T)ransmit commands using N? prefix, as it will result in multiple meters
responding at the same time. 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 the options. If constructing
a value change command (writing data), the numeric data is sent next.

4. 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.

Note: On a change value command (V), if the command string is terminated

with the * character, all values are stored in E

2

PROM memory. Values are

not stored if the $ terminator is used.

Register Identification Chart

1. Register Names are also used as Register Mnemonics during full transmission.
2. The registers associated with the P command are set up in Print Options (Module 7).
3. Unless otherwise specified, the Transmit Details apply to both T and V

Commands.

Command String Examples:

1. Address = 17, Write 350 to Setpoint 1

String: N17VE350$

2. Address = 5, Cycle Counter value, response time of 50 to 100 msec. min.

String: N05TB*

3. Address = 0, Reset Timer value

String: RA*

Transmitting Data To the Meter

Numeric data sent to the meter must be limited to Transmit Details listed in the

Register Identification Chart. Leading zeros are ignored. The meter ignores any
decimal point and conforms the number to the scaled resolution. (ie. The meter’s
scaled decimal point position is set for 0.0 and 25 is written to a register. The value
of the register is now 2.5. In this case, write a value of 250 to equal 25.0).

For RTC Time [C] and Date [D] Value:

Time - 24 Hours, Minutes, Seconds (HHMMSS)

Ex: 083000 = 8:30 AM, 144500 = 2:45 PM

Date - Month, Day, Year (mmddyy)

Ex: 123101 = December 31, 2001

Day - 1 = Sunday through 7 = Saturday

EX: 3 = Tuesday

Notes:

1. Since the meter does not issue a reply to value change commands, follow

with a transmit value command for readback verification.

2. The date and day must be set separately.

Transmitting Data From the Meter

Data is transmitted from 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 is established in Module 7.

COMMAND DESCRIPTION

NOTES

N

Node (Meter) Address
Specifier

Address a specific meter. Must be followed by
node address. Not required when address = 00.

T

Transmit Value (read)

Read a register from the meter. Must be
followed by register ID character.

V

Value change (write)

Write to register of the meter. 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
(read)

Initiates a block print output. Registers are
defined in programming.

ID

VALUE DESCRIPTION

REGISTER

NAME

1

COMMAND

2

A

Timer Value

TMR

6 digit

B

Cycle Counter Value

CNT

6 digit

C

RTC Time Value

TIM

6 digit

D

RTC Date Value

DAT

6 digit

E

Setpoint 1

SP1

6 digit

F

Setpoint 2

SP2

6 digit

G

Setpoint 3

SP3

6 digit

H Setpoint 4

SP4

6 digit

I

Setpoint 1 Off Value

SO1

6 digit

J

Setpoint 2 Off Value

SO2

5 digit

T, V, R

TRANSMIT DETAILS

3

T, V, R

T, V

T, V

T, V, R

T, V, R

T, V, R

T, V, R

T, V

T, V

K

Setpoint 3 Off Value

SO3

6 digit

L

Setpoint 4 Off Value

SO4

6 digit

M Timer Start Value

TST

6 digit

O

Cycle Counter Start Value

CST

6 digit

Q

Timer Stop Value

TSP

6 digit

S

Cycle Counter Stop Value

CSP

6 digit

U

Auto/Man Register

MMR

0 - auto, 1 - manual

W Day of Week Value

DAY

1 = Sun....7 = Sat

X

Setpoint Register

SOR

0 - not active, 1 - active

T, V

T, V

T, V

T, V

T, V

T, V

T, V

T, V

T, V

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