Siemens MicroMaster 440 Control Through S7315 PLC

[JesperMP]

I believe DB50 is oly used by the HMI program. I think it uses tag multiplexing to switch which drive to display when there are several drives in the same project.

As a second issue to this, the drives parameter information keeps resetting to the default values for the drive (230v/50Hz). How can I see the actual drive parameters currently installed, and can I get it retentive to the drive/Profibus module?

If you are modifying the parameter DBs, then be sure to modify the actual vals, not just the initial vals.
Another goofup is to start a "commisioning" by first reading from the drive, thereby loading the factory values.
When you write the parameters to the drive with the commisioning function, then the parameters are stored on the EPROM on the drive.

 

[henno2000]

Here's the block updated to output a word where 16384 corresponds to 100% speed.

FUNCTION FC 4 : VOID
TITLE =
VERSION : 0.1
 
VAR_INPUT
S1_Constant : REAL ; 
P1_Constant : REAL ; 
P2_Constant : REAL ; 
Pressure : REAL ; 
END_VAR
VAR_OUTPUT
wOutput : WORD ; 
END_VAR
VAR_TEMP
rSlope : REAL ; 
rC : REAL ; 
bLess : BOOL ; 
bMore : BOOL ; 
bLinear : BOOL ; 
rTemp : REAL ; 
rSpeed : REAL ; 
diTemp : DINT ; 
END_VAR
BEGIN
NETWORK
TITLE =calc slope
	 A(	; 
	 L	 #P1_Constant; 
	 L	 #P2_Constant; 
	 -R	; 
	 T	 #rTemp; 
	 AN	OV; 
	 SAVE ; 
	 CLR ; 
	 A	 BR; 
	 )	 ; 
	 JNB _001; 
	 L	 #S1_Constant; 
	 L	 #rTemp; 
	 /R	; 
	 T	 #rSlope; 
_001: NOP 0; 
NETWORK
TITLE =calc intercept
	 A(	; 
	 L	 #P2_Constant; 
	 NEGR ; 
	 T	 #rTemp; 
	 SET ; 
	 SAVE ; 
	 CLR ; 
	 A	 BR; 
	 )	 ; 
	 JNB _002; 
	 L	 #rTemp; 
	 L	 #rSlope; 
	 *R	; 
	 T	 #rC; 
_002: NOP 0; 
NETWORK
TITLE =determine which region to use - pressure less than P1
	 L	 #Pressure; 
	 L	 #P1_Constant; 
	 <=R ; 
	 =	 #bLess; 
NETWORK
TITLE =determine which region to use - pressure greater than P1
	 L	 #Pressure; 
	 L	 #P2_Constant; 
	 >=R ; 
	 =	 #bMore; 
NETWORK
TITLE =Linear region
	 AN	#bLess; 
	 AN	#bMore; 
	 =	 #bLinear; 
NETWORK
TITLE =Linear region
	 A(	; 
	 A	 #bLinear; 
	 JNB _003; 
	 L	 #Pressure; 
	 L	 #rSlope; 
	 *R	; 
	 T	 #rTemp; 
	 AN	OV; 
	 SAVE ; 
	 CLR ; 
_003: A	 BR; 
	 )	 ; 
	 JNB _004; 
	 L	 #rTemp; 
	 L	 #rC; 
	 +R	; 
	 T	 #rSpeed; 
_004: NOP 0; 
NETWORK
TITLE =less region
	 A	 #bLess; 
	 JNB _005; 
	 L	 #S1_Constant; 
	 T	 #rSpeed; 
_005: NOP 0; 
NETWORK
TITLE =more region
	 A	 #bMore; 
	 JNB _006; 
	 L	 0.000000e+000; 
	 T	 #rSpeed; 
_006: NOP 0; 
NETWORK
TITLE =scale for drive 0-100 == 0-16384
	 A(	; 
	 L	 #rSpeed; 
	 L	 1.638400e+001; 
	 *R	; 
	 T	 #rTemp; 
	 AN	OV; 
	 SAVE ; 
	 CLR ; 
	 A	 BR; 
	 )	 ; 
	 JNB _007; 
	 L	 #rTemp; 
	 RND ; 
	 T	 #diTemp; 
_007: NOP 0; 
NETWORK
TITLE =scaled value to output
	 L	 #diTemp; 
	 T	 #wOutput; 
	 NOP 0; 
END_FUNCTION

Would there be a reason as to why this code would not work? I have loaded it within the PLC and after about 15 seconds the PLC goes into STOP. From looking in the diagnostic buffer, it details the function where this code is located. (The only change to this code that I have made is replicated another 3 times and created the variables such as #wOutput1, #wOutput2, #wOutput3, #wOutput4 instead of #wOutput)

Regards,
henno2000