Mitsubishi Electric MELSEC iQ-R User Manual page 110

■When oversampling is enabled
An inter-module synchronization cycle is used as a trigger to sample an analog value at 5s cycle. The conversion cycle is
fixed to 5s and A/D conversion values are logged by (Inter-module synchronization cycle/5s) points.
'CH1 Synchronization digital
output value' (Un\G9500)
'Continuous logging start/stop
request' (Un\G100)
'Continuous logging status
monitor' (Un\G61)
Logging timing
digit: Digital output value
t: Time
T : Conversion cycle
1
T : Inter-module synchronization cycle
2
●: Timing of A/D conversion
Ex.
When the inter-module synchronization cycle is 1ms, data of 200 points is logged in an inter-module synchronization cycle.
When the oversampling mode is enabled, the inter-module synchronization cycle is used as a trigger to start
the conversion in all channels in the same way as when the oversampling mode is disabled. However, after
the trigger of the inter-module synchronization cycle, A/D conversion is executed according to the cycle based
on the clock of each A/D converter module. Thus, a time lag in the nanosecond range is generated in every
conversion cycle due to the differences of modules (crystal frequency deviation) or the ambient temperature.
But this does not affect the conversion cycle because the conversion cycle timing is corrected by using the
inter-module synchronization cycle as a trigger.
■Setting procedure
The oversampling mode can be set only with an engineering tool. The default value is "Disable".
1.
Set "Oversampling mode".
[Navigation window]  [Parameter]  [Module Information]  Module model name  [Application setting] 
[Oversampling mode]
2.
Set "Fixed Scan Interval Setting of Inter-module Synchronization" as shown below.
[Navigation window]  [Parameter]  [System Parameter]  [Inter-module Synchronous Setting]  [Fixed Scan
Interval Setting of Inter-module Synchronization]
Item
0.05ms Unit Setting
Fixed Scan Interval Setting
If "Fixed Scan Interval Setting of Inter-module Synchronization" is not set as shown above, a synchronization cycle time
setting enabled range error (error code: 1EA0H) occurs. When oversampling is disabled, there are no restrictions on the
setting of "Fixed Scan Interval Setting of Inter-module Synchronization".
1 FUNCTIONS
108
1.15 Continuous Logging Function
digit
Synchronous conversion value
Stop (0)
Continuous logging start request waiting (1)
T
2
T T
1 1
Synchronous conversion value Synchronous conversion value
Start (1)
Continuous logging in process (2)
Setting details
Set
1ms or less
t
T T T T
1 1 1 1