Read Register Command Code: T; Write Register Command Code: V; Reset Alarm Command Code: R; Control Action Command Code: C - Omega CN63100 Series User Manual

Read Register Command Code: T

The Read Register command is used to read data from a register. This
command must be followed by a Register ID character. In full response mode,
the controller responds to this command by transmitting its Address (if
greater than 0), corresponding register mnemonic and register data. In
abbreviated response mode, the controller transmits data only. The response
time to this command is controlled by the type of termination character. This
is a single register response.

Write Register Command Code: V

The Write Register command is used to write data to a register. This
command must be followed by a Register ID character and Numeric Data. A
unique command line is required for each register write operation. No
response occurs for invalid write operations. The Read Register command
(T) can be used for readback verification.

Reset Alarm Command Code: R

The Reset Alarm command resets the alarm outputs. This command must
be followed by a Register ID character (G for Alarm 1, and H for Alarm 2).
This command does not alter the actual alarm mode or value setting.

Control Action Command Code: C

The Control Action command is used to affect certain controller operating
modes.The registers used with this command are: Auto/Manual mode select,
Auto-Tune mode select, and Remote Setpoint mode select. After the Register
ID character, either a "1" or "2" is sent to set a specific controller mode.

Block Read Register Command Code: P

The Block Read Register command is used to read data from multiple
registers with a single command. With this command, if no register ID
characters follow, the controller responds with register data that is preset by
the Print Options parameter (Module 6-SC). This mode is useful for print
ticket applications. However, if Register ID characters follow this command,
the controller responds with register data indicated by the ID character field.
This character ID field does not follow the normal Register ID format, but
instead is a field composed of ASCII encoded bit mapped bytes. (See Block
Read Command Register ID Table.)
Four of these field bytes are used in this format:
P<Byte1><Byte2><Byte3><Byte4>
Each byte represents a code that selects a register(s) for transmission. The
Block Read Command Byte Table relates specific registers for reads to the
field bytes.
Examples:
Print: Alarm 1 and Alarm 2 values (both are in Byte2 table)
Explanation: Byte1 = 0, Byte2 = 3, Byte3 & Byte4 are not needed
ASCII String : P03* (Either the "*" or "$" terminator could be used.)
For those programming in HEX: P = <50>, 0 = <30>, * = <2A>, $ = <24>
HEX String : <50><30><33><2A>
Print: Input, Cooling Deadband and Output Status (Input is in Byte1 table
and the other two are in Byte4 table)
Explanation: Byte1 = 8, Byte2 = 0, Byte3 = 0, Byte4 = C
ASCII String : P800C$ (Either the "*" or "$" terminator could be used.)
HEX String : <50><38><30><30><43><24>

Terminator : * or $

After a Read Register command is sent, the response time of the controller
is determined by the type of command terminator character. The "$"
terminator causes a response time of 2 msec to 100 msec and the "*"
terminator causes a response time of 100 msec to 200 msec. (The 2 msec delay
allows for a two character transmission time at 9600 baud. ) The controller
does not begin processing the command string until the "$" or "*" is received.
The Carriage Return <CR> and the Line Feed <LF> cause the controller to
ignore the command string. When writing setpoint values, only values using
the "*" terminator are saved to E
-59-
2
PROM memory.