Yokogawa DAQWORX - Manual (Page 29)

3-6 IM WX1-05E
Group Names
You can assign names to groups. Names can contain up to 30 alphanumeric characters.
The group names specified here are the default values when Remote Monitor is
connected to GateMODBUS.
Acqurng Data at Fxed Intervals
Using GateMODBUS, data can be acquired concurrently on each port. Therefore
data is logged more efficiently when connecting each Modbus device to a separate
port rather than connecting several Modbus devices to a single port. Also, registers
occurring in a continuous sequence on 1 instrument are read all at once. Therefore, the
more sequentially continuous registers there are, the more efficiently data is acquired.
However, if a register within the sequence experiences an error, the error applies to all
registers in the sequence.
For example, given the three registers below, TAG001–TAG003 are read all at once at
each scan interval.
Tag COM Port Modbus Address Regster numbers read
TAG001 COM1 1 30001
TAG002 COM1 1 30002
TAG003 COM1 1 30003
Data Dropout
If data is being read at the timing shown below, data is dropped. Data dropout can occur
in the following circumstances.
• If the tme requred to read the tags s longer than the scan nterval
In the figure below, by the time the tags at T1 have been read, T2 has already passed
and T3 begins. Therefore, the tags to have been read at T2 were dropped.
TAG001 TAG002 TAG003 TAG004 TAG001 TAG002 TAG003 TAG004
T T1 = T + ∆ t T2 = T + ∆ t x 2 T3 = T + ∆ t x 3
Interval: ∆ T
Data reading at time T Data reading at time T1
Time
Data
dropout
occurs
Time
Timing of Data Reading
3.2 Detaled Descrpton of Functons