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OPC Explorer

The OPC explorer is a sample OPC client provided for interoperability testing purpose and user experimentation of the OPC interface. It can be used view data from local or remote OPC server.

OPC Server

Server Name User supplied name of OPC Server.
OPC Server Name of Server.
Remote Node Machine where Server is running. Left blank if the Server is local.
Start Time Time the Server was started.
Current Time Time reported by Server.
Vendor Info Server vendor information
Server State State of Server
Group Count Number of groups currently created
Bandwidth Percentage bandwidth used
Major Major version number
Minor Minor version number
Build Build number
Reserved Reserved

OPC Group

Any number of groups may be defined for each server.


Group Name User supplied group name. Must be unique.
Update Rate Acquisition rate for this group.
Deadband Only items whose values changes by more than deadband will be reported. The raw low and raw high value must be defined.
Time Bias Time bias in minutes.
LCID Locale ID.
Client Handle Client Handle.
Server Handle Handle allocated by OPC Server.
Active Set to 0 to disable group.
OPC 2 Force the use of OPC 2.0 even if the OPC 1.0 interface is published by the OPC Server.
TimeStamp Time stamp information is required.
Read Type Type of read to be performed
Exception Only changes will be reported.
Refresh Poll entire group continuously. Data is returned later when they are read.
Async Poll every item in group continuously. Data is returned later when they are read.
Sync Poll every item in the group continuously. Data is returned immediately.
Read Source Where to read data from
Device Cause an request to be sent to the device to acquire the data.
Cache Data is returned from the OPC Server cache.
Write Type Type of write to be performed.
Async Do not wait for write to be completed.
Sync Wait for write to be completed.


ItemID Current Item ID .
Interval Interval between writes.
Increment The next value to be written will be increment by this value.
Running When running is enable, all items in the Write List will be written to at the interval configured for them.
Value Current value.
Low Low value. When the current value is below the low value, it will be set to the high value.
High High value. When the current value exceeds the high value, it will be set to the low value.
Available Items List of items that can be simulated.
Write List List of active write items.
>> Add selected items in available list to Write list.
<< Delete selected items in Write List.

OPC Item

Any number of items may be defined for each group.

Item ID
Access Path
Active Set to 0 to disable item
Data Type
Raw Data Type
Value Last value read
Time Stamp Last time stamp
Quality Last quality
Access Rights
Client Handle
Server Handle

OPC Item History

The last 16 events of the item is displayed.

Time Time stamp of event.
Delta (ms) Time difference from previous event.
Type Event type
->Read Issue read request
<-Read Read completed
->Write Issue write request
<-Write Write completed
Value Read value.
Quality Quality of read value.
Time Stamp Time stamp of read value.
XID Transaction ID
Reserved Not used.

FAQ for OPC Explorer

Q:Is it possible to setup IOServer to write the value of zero to a tag every Midnight?

A:In IOServer OPC Explorer, use the PLC simulator to write to the tag. Use the following settings:
Interval: 86400000 ms
Increment, Value, Low, High: 0
Enable Running
The PLC simulator will issue a write of 0 to that tag a couple of milliseconds after every midnight. The interval is synchronized to the PC clock. Make sure that the PC clock is correct. The write will be performed when it is first configured or when IOServer is started. Subsequence writes will be performed immediately after midnight.

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Last updated: Sat, 20 Feb 2021 05:17:52 GMT