76
In automatic mode
(auto = true) ) PID ouput has following value :
“Error” (error value displayed in D92) = SP - PV;
“LMN_P” (proportional part displayed in D89) = filtered (KP * Error);
“LMN_I” ((integral part displayed in D90) = LMN_I + (KP * Error / (T_DRW_PWM * TI);
“LMN_D”( derivative part displayed in D91)=TD*KP*(Error - Error_Last)*T_DRW_PWM;
“XOUT” (PID regulator output displayed in D93) = LMN_P + LMN_I + LMN_D
Whereas T_DRW_PWM = 1000 / P101 with P101 = PWM frequency and Error_Last is the error
value of the previous control cycle.
N.B. In the folder “PID Controller” with the parameter "EN_PID" ( P249 - Enabling Genera PID
Control) is possible to disable the PID control function. If this parameter is disabled the PIC
control is not active.
4 FIELDBUS
4.1 MODBUS PARAMETERS
The OPEN drive products line is compatible with the protocol of the serial communication Modbus
rtu.
At a physical level , the supported standard is the RS485, see the drive installation manual for
information about it. Specifications about the Modbus Protocol are available at the Internet address :
www.modicon.com/TECHPUBS/intr7.html
4.1.1 APPLICATION CONFIGURATION
4.1.1.1 NODE CONFIGURATION
The drive configuration as Modbus node requires the correct configuration of the following
parameters:
Name Description Range Default
P92 Serial identification number
0÷255
1
P93 Serial baud rate 19,2 ; 38,4 ; 57,6 19,2 Kbit/s
By setting these parameters in real time, they will become instantly active :
Note: the communication mode in broadcast with address = 0 is not managed
Name Description Min Max Default UM Scale
MODBUS_ADDR P92 - Serial identification number 0 255 1 1
MODBUS_BAUD P93 - Serial baud rate 192 Kbit/s 1
To Next Page
Loading...
