take readings from Lakeshore 336 T controller through VISA TCPIP, but very slow

[weitong]

I connected a Lakeshore 336 Temperature controller to a PC ethernet card by using a normal RJ45 cable.
The VISA resource name is set as "tcpip::192.168.0.12::7777::socket". But the readings is very slow. It takes about 2 seconds for reading one sensor data. But the manual says "10 readings/second".

I tried both Lakeshore 336 Temperature controller and PC connected to a router, but the same slow speed.
How can I get reading as fast as GPIB interface using Ethernet port?

Thanks.

LV2013SP1@Win7Pro
WT

[weitong]

Attached are the snapshots of the front panel and block diagram (with 2 probes) of the VI reading LS336 sensor.

There are 2 probes inserted. One is right after VISA Write, which shows no error; the other one is right after VISA Read, which shows error. But strangely,  the VI still acquires the sensor readings correctly even the error occurs.

Thanks in advance.

WT

[weitong]

By several days trials, I found the reason.

The byte count set to the VISA read function have be to equal or less than the return bytes by the instruments. Otherwise, timeout (slow response) happens.

I don't understand why VISA-TCP/IP cannot work like VISA-GPIB which can automatic accept the returned bytes no matter how many byte count I set to the VISA read function.

WT