
Parker RAC Europe
PSD04 | User manual ver. 3.6 | Code 144PSDI364
Page 53 of 74
8
SERIAL COMMUNICATION
8.1
Preliminary information
It is possible to control the PSD04 driver by connecting it to a controller.
The controller sends information to the driver necessary for it to correctly control its functions, and the driver responds,
communicating internal information, such as the pressure and temperature measurements, alarms, etc.
The connection methods available on the PSD04 are CANBUS, MODBUS RS-485, and MODBUS on the setting and
programming port, according to the model.
The protocol to be used for communication with the controller must be selected via the parameter in the Enabling
mode (Pr06).
8.2
CANBUS serial communication
The PSD04 controller primarily uses a protocol based on CANBUS for communication with controllable systems.
The exchange of data is based on a list of variables or parameters that the controller may send to the driver, and a list
of variables the driver sends to the controller to provide its state data.
The PSD04 status variables are:
AI1 type
AI2 type
Ai error timeout
FSM status
(Stat)
Used SH control parameters set
(SetS)
Measured SH
(SH)
Used SH set-point
(SpSH)
Measured aspiration temperature
(Ts)
Measured evaporator pressure
(Pe)
Calculated evaporator temperature
(Te)
Unit uf measure in use
(UdM)
Working hour
(Pr40)
Control algorithm status
(AlgS)
Alarm status
(AlSt)
Configuration warning
(CoWa)
Enable valve status
(EnaS)
Request a reset status
(ParS)
Resynchro request status
(ResS)
Target position
(Psp)
Current valve position %
(PAtt)
Communication alarm enable status
(Pa01)
Communication alarm delay
(Pa02)
FW project
FW variation
FW version
FW revision
The control variables are:
AI1 type
AI2 type
Ai error timeout
Enable valve command
(EnaV)
Command
(Cmd)
Resynchronization request
(ResR)
Functioning mode
(Pr02)
Manual valve position set-point
(Pr03)
Debug valve step rate
(Prd0)
Debug minimum opening
(Prd1)
Debug maximum opening
(Prd2)
Stabilization delay
(Pr08)
Stabilization position
(Pr09)
Main control type
(PCty)
SH control parameters selection
(SEtP)
set 1: SH set-point
(Pc01)
set 2: SH set-point
(Pp01)
set 1: LoSH set-point
(Pc02)
set 2: LoSH set-point
(Pp02)
set 1: HiSH set-point
(Pc03)
set 2: HiSH set-point
(Pp03)
set 1: LOP set-point
(Pc04)
set 2: LOP set-point
(Pp04)
set 1: MOP set-point
(Pc05)
set 2: MOP set-point
(Pp05)
set 1: PID proportional band
(Pc13)
set 2: PID proportional band
(Pp13)
set 1: PID integral time
(Pc14)
set 2: PID integral time
(Pp14)
set 1: PID derivative time
(Pc15)