Mitsubishi Electric MELSEC iQ-R Series - Calculating the Common Logarithm

26 SINGLE VARIABLE FUNCTIONS
26.4 Calculating the Common Logarithm
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26.4 Calculating the Common Logarithm
LOG(_E)
These functions output the common logarithm (logarithm with base 10) of an input value.
Setting data
■Description, type, data type
Processing details
■Operation processing
• These functions calculate the common logarithm of the REAL or LREAL data type value input to (s), and output the
operation result from (d).
• When the input value is defined as A and the output value is defined as B, the relationship of A and B will be as follows:
B=log
10
A
• Input a REAL or LREAL data type value to (s).
• Input a positive value only. (Calculation cannot be performed with a negative value.)
• If the operation result is -0 or an underflow occurs, 0 will be output as the operation result.
■Operation result
1. Function without EN/ENO
The operation processing is performed. The operation result is output from (d).
2. Function with EN/ENO
The execution conditions and operation results will be as follows.
*1 If the value FALSE is output from ENO, the output data from (d) will be undefined. Create a program so that the undefined value will not
be used in operations.
Ladder, FBD/LD Structured text
[Without EN/ENO] [With EN/ENO] [Without EN/ENO]
d:=LOG(s);
[With EN/ENO]
d:=LOG_E(EN,ENO,s);
Argument Description Type Data type
EN Execution condition (TRUE: Executed, FALSE: Not executed) Input variable BOOL
s (IN) Input Input variable ANY_REAL
ENO Output status (TRUE: Normal, FALSE: Abnormal) Output variable BOOL
d Output Output variable ANY_REAL
Execution condition Operation result
EN ENO (d)
TRUE (executed) TRUE Operation result output value
FALSE (not executed) FALSE
*1
Undefined value
RnCPU
RnENCPU
RnSFCPU RnSFCPURnPCPURnPCPU
(Standard) (Safety)
(Redundant) (Process)
sd
EN ENO
ds