PXU20030 Datasheet, PDF (20/32 Pages) Red Lion Controls. Inc – MODEL PXU - TEMPERATURE/PROCESS CONTROLLERS

SERIAL COMMUNICATIONS
When using a PXU with RS485 communications option, the PXU will support Modbus communications. Unit configuration,
as well as data interrogation, can be accomplished through Modbus communications. The PXU allows for 32 Read / Write
registers. A complete list of Modbus registers is available at the end of this document.
CRIMSON SOFTWARE
Crimson is a Windows^® based program that allows configuration of the PXU
controller from a PC. Crimson offers standard drop-down menu commands to
make it easy to program the PXU controller, the PXU database can then be
saved in a PC file for future use. The Crimson 2.0 software is available at www.
redlion.net. An RS-485 PC card or USB to RS485 converter and cabling is
required. Prior to downloading or extracting the database, the PXU must be set
to Modbus RTU communications type. The proper communications port, baud
rate, and unit address must be configured in the Link, Options dialog and must
match the baud rate and unit address configured in the PXU serial communications
module (7-SC).
PXU CONFIGURATION USING CRIMSON
1. Install Crimson software, available for download at www.redlion.net.
2. Connect communications cable from PXU to PC.
3. Supply power to PXU.
4. Configure serial parameters as Modbus RTU (rtu), 38,400 baud, address
247.
5. Create a new file (File, New) or open an existing PXU database within
Crimson.
6. Configure Crimson 2 Link options (Link, Options) to the serial port which the
communication cable is attached (in step 2).
7. Select Update (Link, Update).
PXU FREQUENTLY USED MODBUS REGISTERS
Only frequently used registers are shown below. The entire Modbus Register Table can be found at the end of this document.
The following is an example of the necessary query and corresponding response for holding register 2. In this example register 2 is the decimal value 123.
Query: 01 03 00 01 00 01 D5 CA
Response: 01 03 02 00 7B F8 67
Notes:
1. The PXU registers can be read as holding (4x) or input (3x) registers.
2. The PXU should not be powered down while parameters are being changed. Doing so may result in an in-complete write to the non-volatile memory and produce
checksum errors.
REGISTER (4x)
REGISTER NAME
1
Process Value (PV)
2
Active Setpoint (SP)
3
Setpoint 1 (SP1)
4
Setpoint 2 (SP2)
5
Setpoint Deviation
6
Alarm 1 Value
7
Alarm 2 Value
8
Alarm 3 Value
9
Output Power 1
10
Output Power 2
11
PB Proportional band (Active)
12
Integral time (Active)
13
Derivative time (Active)
14
Integration default (Active)
15
PID parameter set selection
16
Auto-Tune Start
17
Control Mode Transfer (Auto/Manual)
18
Controller Status
19
Setpoint Select
20
SP Ramp Rate
21
LED Status
22
Pushbutton Status
23
Alarm Reset
24
Setpoint Ramping Disable
25
Integral Action Disable
LOW LIMIT
N/A
-999
-999
-999
N/A
-999
-999
-999
0
0
1
0
0
0
0
0
0
0
0
0
N/A
N/A
0
0
0
HIGH LIMIT
N/A
FACTORY
SETTING
N/A
9999
0
9999
0
9999
0
N/A
N/A
9999
100
9999
200
9999
300
1000
0
1000
0
999(.9)° or
9999 (process)
70
9999
120
9999
30
1000
0
1
0
1
0
1
0
1
1
1
0
9999
0
N/A
N/A
N/A
N/A
7
0
1
0
1
0
ACCESS
COMMENTS
Read 1 = 1 Display unit
Read/Write 1 = 1 Display unit
Read/Write 1 = 1 Display unit
Read/Write 1 = 1 Display unit
Read Only 1 = 1 Display unit
Read/Write 1 = 1 Display unit
Read/Write 1 = 1 Display unit
Read/Write 1 = 1 Display unit
Read/Write 1 = 0.1%; writable when in manual mode only.
Read/Write 1 = 0.1%; writable when in manual mode only.
Read/Write 1 = 1 Display unit
Read/Write 1 = 1 second
Read/Write 1 = 1 second
Read/Write 1 = 0.1 % output power
Read/Write 0 = PID Set 1, 1 = PID Set 2
Read/Write 0 = No; 1 = Yes
Read/Write 0 = Automatic (PID), 1 = User (Manual Mode)
Read/Write 0: Stop, 1: Run
Read/Write 0=SP1, 1=SP2
Read/Write 1 = 1 Display unit/minute
Read Only
b0: ALM3, b1: ALM2, b2: F, b3: C, b4: ALM1,
b5: OUT2, b6:OUT1, b7: AT
Read Only
b1: F2, b2: Down, b3: P, b5: F1, b6: Up, b7: D;
0 = Key pressed, 1 = Key not pressed
Write b0: Reset Alm1, b1: Reset Alm2, b3: Reset Alm3
Read/Write 0 = Enabled, 1 = Disabled
Read/Write 0 = Enabled, 1 = Disabled
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