Convert to Python to Codesys
Draft
The PI-Plate has manufactures devices that can be used with the Raspiberry-PI. The objective of this project would not stop at just the relay plate, but also incorporate other Pi-Plate devices. The Device driver will be a child of the SPI master and have 7 slots for Pi-Plate devices.
Pi-Plates
Data Acquisition Plate with Generator Capabilities
Data Acquisition Plate
Tinker Plate, Mix of Data Acquisition and inputs
Relay Control
Temperature Measurement
Motion Control
https://pi-plates.com/pi-plates-catalog/
The relay plate has 7 relays on the plate. Looks like it is because of size and cost constraints. Stacking the plates will allow for 49 relays. Which is plenty for most projects and there is always the possibility of stringing together multiple Rasp-PIs via ethercat. Each relay will be mapped to a variable so true will be on and false will be off.
RELAY Control Functions
relayON(addr,relay) - turns on (closes) the specified relay
relayOFF(addr,relay) - turns off (opens) the specified relay
relayTOGGLE(addr,relay) - "toggles" state of specified relay. If relay is on, this command will turn it off. If relay is off, this command will turn it on. Use this command to blink a lamp off and on.
relayALL(addr,value) - used to control the state of all relays with a single command. "value" is a 7 bit number with each bit corresponding to a relay. Bit 0 is relay 1, bit 1 is relay 2, and so on. To turn all the relays on at once, use the number 127 for the value.
* relaySTATE(addr) - Returns a 7-bit number with the current state of each relay. Bit 0 is relay 1, bit 1 is relay 2, and so on. A "1" in a bit position means that the relay is on and zero means that it's off.
LED Control Functions
setLED(addr) - turn on the LED
clrLED(addr) - turn off the LED
* toggleLED(addr) - if LED is on, turn off. If LED is off, turn on.
System Level Functions
getID(addr) - return Pi-Plate descriptor string
getFWrev(addr) - return FW revision in byte format
getHWrev(addr) - return HW revision in byte format
getPMrev() - returns revision of python module
getADDR(addr) - return address of pi-plate. Used for polling available boards at power up.
RESET(addr) - set RELAYplate to power-on state. Turns all relays off. **
I am going to focus on
RelayAll
setLED
clrLED
getFWrev
getHWrev
RESET
- Python Code
def getHWrev(addr): global RELAYbaseADDR VerifyADDR(addr) resp=ppCMDr(addr,0x02,0,0,1) rev = resp[0] whole=float(rev>>4) point = float(rev&0x0F) return whole+point/10.0 def getFWrev(addr): global RELAYbaseADDR VerifyADDR(addr) resp=ppCMDr(addr,0x03,0,0,1) rev = resp[0] whole=float(rev>>4) point = float(rev&0x0F) return whole+point/10.0 def relayALL(addr,relays): VerifyADDR(addr) assert ((relays>=0) and (relays<=127)),"Argument out of range. Must be between 0 and 127" ppCMDr(addr,0x13,relays,0,0) def ppCMDr(addr,cmd,param1,param2,bytes2return): global RELAYbaseADDR arg = list(range(4)) resp = [] arg[0]=addr+RELAYbaseADDR; arg[1]=cmd; arg[2]=param1; arg[3]=param2; GPIO.output(ppFRAME,True) null=spi.xfer(arg,300000,60) #null = spi.writebytes(arg) if bytes2return>0: time.sleep(.0001) for i in range(0,bytes2return): dummy=spi.xfer([00],500000,20) resp.append(dummy[0]) time.sleep(.001) GPIO.output(ppFRAME,False) time.sleep(.001) return resp **Codesys Code:** FB_Relay_Plate //Globals Hardware_Version : BYTE; Firmware_Version : BYTE; Relay_Plate_Address : BYTE; //0 to 7 Assigned by slot address? Relay_States : BYTE; //0 to 127, Bit 0 = Relay 0, Bit 7 = Relay 7 Led_State : BOOL; //True = On, False = Off Previous_State : BYTE; End VAR CONSTANT Relay_Base_Address : BYTE := 24; Frame_GPIO : BYTE := 25; PPINT : BYTE := 22; END_VAR Intialize Method Set_Address Method Get_Hardware_Version : BYTE; Method Get_Firmware_Version : BYTE; Cyclic Calls METHOD Set_IO VAR Previous_Relay_State : BOOL; Previous_LED_State : BOOL; Send_Data : BOOL; CommandData : ARRAY [0..6] OF BYTE; END_VAR Write_Data(Data:=CommandData,Execute:=Send_Data, Data_Sent => DataSent); Case of iState Set_Relays: IF Previous_State <> Relay_States Send_Data := True; (*Format: ppCMDr(addr,0x13,relays,0,0) arg[0]=addr+RELAYbaseADDR; arg[1]=cmd; arg[2]=param1; arg[3]=param2; null=spi.xfer(arg,300000,60) 300000 = 0x93E0; 60 = 0x3C; *) CommandData[0] := Relay_Base_Address + Relay_Plate_Address; CommandData[1] := 16#0x13; //COMMAND FOR ALL RELAYS CommandData[2] := Relay_States; //CURRENT RELAY STATE MAP CommandData[3] := 16#0x04; //Don't know what the rest does CommandData[4] := 16#0x93; CommandData[5] := 16#0xE0; CommandData[6] := 16#0x3C; If DataSent Then Relays_Set := true; Send_Data := False; Previous_State := Relay_States; End_IF Else Relays_Set := true; End_IF If Relays_Set = True Then Send_Data := False; Previous_State := Relay_States; iState := Set_Leds; End_IF Set_Leds : Function Write_Data VARINPUT bExecute : BOOL; Data_Command : ARRAY [0..6] OF BYTE; END_VAR VAR iStep : INT; VAR_END VAR OUTPUT Data_Sent : BOOL; VAR_END IF bExecute Then //Set frame GPIO //On_Output //Not sure how to do this yet //Send 1 byte at a time senddata(Data:= Data_Command[iStep]); //move to the next byte iStep := iStep + 1; //if last byte then reset and indicate last data sent if iStep = 7 Then iStep := 0; Data_Sent := True //Turn the output off //Not sure how to do this yet. End_IF Else //Reset Function if not executing iStep := 0; Data_Sent := False; End_If; Method sendData : BOOL; VAR_INPUT DATA : BYTE; END_VAR VAR abyTxBuffer: ARRAY [0..2] OF BYTE; abyRxBuffer: ARRAY [0..2] OF BYTE; END_VAR abyTxBuffer[0] := DATA; //SPI_WRITE_CMD; abyTxBuffer[1] := byPort; abyTxBuffer[2] := byValue; Write_Data := transfer(pabyTxBuffer:=ADR(abyTxBuffer) , pabyRxBuffer:=ADR(abyRxBuffer) , udiLen:=3 , uiDelayus:=5 ); IF NOT Write_Data THEN _iState := 1000; END_IF