We used a VB demo to test the
performance (polling) of reading data from NAPOPC DA Server and
received the following performance data:
Version |
Process UI |
From Cache |
From Device |
1 |
Version |
Process UI |
From Cache |
From Device |
1.31 |
Yes |
601 |
228 |
1 |
2.11 |
Yes |
1716 |
1 |
1.31 |
No |
1058 |
263 |
1 |
|
|
|
|
2.00 |
Yes |
1095 |
268 |
1 |
1 |
1 |
1 |
1 |
2.00 |
No |
3122 |
324 |
1 |
|
|
|
|
2.03 |
Yes |
1141 |
318 |
1 |
|
|
|
|
2.03 |
No |
3101 |
398 |
1 |
|
|
|
|
|
|
|
|
1 |
|
|
|
|
Unit |
Readings/Sec (Readings per Second) |
1 |
Unit |
Readings/Sec (Readings per Second) |
Modules |
I-7520,
I-7011 |
1 |
Modules |
I-7520,
I-7012 |
Channel |
0 |
1 |
Channel |
0 |
Data Type |
floating point value (Analog Input) |
1 |
Data Type |
floating point value (Analog Input) |
Baud Rate |
115200 BPS |
1 |
Baud Rate |
115200 BPS |
Checksum |
disabled |
1 |
Checksum |
disabled |
Data format |
N-8-1 |
1 |
Data format |
N-8-1 |
timeout |
200 milliseconds |
1 |
timeout |
200 milliseconds |
CPU |
PII 300MHz |
1 |
CPU |
P4 1.6GHz |
RAM |
128 MB |
1 |
RAM |
512 MB |
Platform |
Windows NT 4.0 (SP3) |
1 |
Platform |
Windows XP Professional 2002 SP1 |
This VB demo program uses the Automation
Interface to access the OPC. In the background, the Automation
Interface goes through the COM interface to access OPC. Thus,
this may cause the lower performance.
User's programs can also access the OPC
server via the COM interface directly. This may cause more
complicated codes, but result in better performance.