Mitsubishi Electric MELSEC iQ-R Series User Manual page 79

CH1 Overflow detection flag
When the count type is linear counter, the overflow detection status can be checked.
Monitored value
0
1
■Buffer memory addresses
The following shows the buffer memory addresses of this area.
Buffer memory name
CH Overflow detection flag
CH Overflow detection flag (when Q series-
compatible mode is used)
■Overflow detection flag status
• When an overflow occurs, Overflow detection (1) is stored in 'CH1 Overflow detection flag' (Un\G6). An overflow occurs
when 'CH1 Accumulating count value' (Un\G2, Un\G3) exceeds 99999999.
• At the same time as the occurrence of an overflow, an overflow error (error code: 1900H) occurs and the count operation
stops. 'CH1 Accumulating count value' (Un\G2, Un\G3) is fixed to 99999999 and 'CH1 Sampling pulse number' (Un\G0) is
reset to 0. After an overflow error occurs, 'CH1 Accumulating count value' (Un\G2, Un\G3) remains fixed to 99999999 even
if a pulse is received.
■Clearing the overflow detection flag
• Setting 'CH1 Counter reset request' (Un\G386) to Reset request (1) causes No overflow detection (0) to be stored in 'CH1
Overflow detection flag' (Un\G6). At the same time, the overflow error (error code: 1900H) is cleared and the count
operation restarts.
• Turning off and on 'CH1 Error reset request' (Y8) does not restart the count operation. To restart the count operation, it is
necessary to turn on and off 'Operating condition setting request flag' (Y1) or to set 'CH1 Counter reset request' (Un\G386)
to Reset request (1).
CH1 Carry over detection flag
When the count type is ring counter, the carry over detection status can be checked.
Monitored value
0
1
■Buffer memory addresses
The following shows the buffer memory addresses of this area.
Buffer memory name
CH Carry over detection flag
CH Carry over detection flag (when Q series-
compatible mode is used)
■Carry over detection flag status
• When a carry over occurs, Carry over detection (1) is stored in 'CH1 Carry over detection flag' (Un\G7). A carry over occurs
when 'CH1 Accumulating count value' (Un\G2, Un\G3) exceeds 99999999.
• When a carry over occurs, the count operation continues without stopping. No error occurs.
■Clearing the carry over detection flag
No carry over detection (0) is stored in 'CH1 Carry over detection flag' (Un\G7) with the following methods.
• Setting 'CH1 Carry over reset request' (Un\G387) to Reset request (1)
• Turning off and on 'Operating condition setting request flag' (Y1)
Description
No overflow detection
Overflow detection
CH1 CH2 CH3
6 22 38
12 44 76
Description
No carry over detection
Carry over detection
CH1 CH2 CH3
7 23 39
14 46 78
CH4 CH5 CH6
54 70 86
108 140 172
CH4 CH5 CH6
55 71 87
110 142 174
Appendix 3 Buffer Memory Areas
CH7 CH8
102 118
204 236
A
CH7 CH8
103 119
206 238
APPX
77