Yokogawa DR240 - Manual (Page 204)

12-2 IM DR231-01E
12.1 Overview of the Computation Function
Statistical operators within the group
Type Operator Example Description
Maximum value CLOG.MAX() CLOG.MAX(G01) Obtain the maximum value of the measured data of group G01.
Minimum value CLOG.MIN() CLOG.MIN(G02) Obtain the minimum value of the measured data of group G02.
Max-min value CLOG.P-P() CLOG.P-P(G03) Obtain the P-P value of the measured data of group G03.
Total value CLOG.SUM() CLOG.SUM(G04) Obtain the total value of the measured data of group G04.
Average value CLOG.AVE() CLOG.AVE(G05) Obtain the average value of the measured data of group G05.
* Statistical computation of the measured data of the input channel within the same group measured at the
same time every specified interval.
Special operators
Type Operator Example Description
Previous value* PRE() PRE(001) Obtain the previous measured data of channel 001
Hold** HOLD(): HOLD(001):TLOG.SUM(002) When the measured value of channel 001 changes from
0 to a nonzero value, maintain the integrated value of the
measured data of channel 002 while the measured value
of channel 001 is nonzero.
Reset** RESET(): RESET(001):TLOG.SUM(002) When the channel 001 = nonzero, reset the integrated
value of the measured data of channel 002
* Previously measured data or computed data. In the case of computed data, the value is set to 0 when the
computation is reset. At the start of the computation, if the computation was reset, the value is “0”. If it
was not reset, the value is the last value of the previous computation. The value that can be specified
inside the() is limited to the input channel number (001 to 030) or the computation channel number (A01
to A30). Each computing equation can be used once.
** When specifying HOLD(A):B or RESET(A):B, A and B are channel numbers or computing equations.
These can be used once in the beginning of the computing equation.
Limitations in computing equations
Multiple operators can be used in 1 computing equation. But, there are following limitations.
- Number of characters that can be used : 40 characters
- Total number of channel numbers and constants: 16 (Computation erroro ccurs when 16
exceeded, and the computed result becomes +OVER or -OVER)
- Computation channel numbers: Computation channel numbers less than the current
computation channel number can be used as variables within the computing equation.
Example: A02=001+A01
← Computation channel numbers greater than or equal to A03 can
not be used in this computation.
- Statistical operators (TLOG. or CLOG.) can only be used once in 1 computing equation.
Computation channel
A total of 30 computation channels are available (A01 to A30).
Constant
A total of 30 constants can be set (K01 to K30).
Flag (F01 to F16)
Flags can be set in computing equations as constants (1 or 0). Flags are normally 0, but it is set to
1 when a certain event occurs according to the event/action function. For example, if the
computing equation is set to
NOTF01*TLOG.SUM(001),
and FLAG:F01 is set as an edge action of an event/action, F01 becomes 1 when the event occurs.
This causes NOTF01 to become 0 and the SUM of channel 001 to become 0.
Computation range
If the result exceeds ±10 308 during computation, an overflow will occur.
Data applicable for computation
The following data is used for computation.
• Measured data: Specified by channel No. (DR130: 001 to 020; DR231/241: 001 to 030)
• Computed data: Specified by computation channel No. (A01 to A30).
• Constant: Value specified for K01 to K30.
• Group data: Measured data of channels belonging to a group. Specified by group No. (G01 to
G07). This is applicable only for CLOG.
• Communication input data: Data written to the instrument’s memory via communication
interface. Specified by data No. (C01 to C30).
• Data on internal RAM disk: Applicable only for the DR130-1/DR231-1/DR241-1 (equipped
with a floppy disk drive). Measured/computed data saved in the internal RAM disk. Use the
following numbers to specify data.
Measured data:
DR130: M001 to M020
DR231/241: M001 to M030