Cannot program USB-8452 into I2C High Speed Mode 3.33MHz

[DennyTsao]

Hi, I am using the USB-8452 as I2C high speed host (1.11MHz ~ 3.33MHz) to access slave IC. But I cannot program the host into 3.33MHz with "NI USB-854x I2C Configuration" in the driver. The max speed only reach 1MHz (Fast Mode Plus) thru scope observation. Please tell me what's wrong in my program? Thanks in advance.

[Ting1224]

Hi,

Do you currently use the NI-845x driver version later than 2.1?

Please check the following message.

http://www.ni.com/pdf/manuals/373865a.pdf

The NI USB-8452 in this kit has been updated to a firmware version that is
incompatible with NI-845x driver versions prior to 2.1. If an NI-845x driver
version prior to 2.1 is installed on your system, you need to upgrade your
driver by using the enclosed installation CD or downloading the latest
NI-845x driver from ni.com/downloads.
If you cannot upgrade the NI-845x driver on your system, you can refer to
an online document for additional options. Visit ni.com/info and enter
the Info Code 8452FW.

BR

Ting

[GPIB_Guru]

The basic API property nodes for HS clock rate are unused in the scripting API. Use the scripting API HS enable and HS clock rates modes.

Also.. why are you not just using the basic API I2cWriteRead call? That is more efficient and easier to program that using the scripting API. Especially since you are doing nothing that requires the flexibility of the scripting API.

[DennyTsao]

Thanks you all for the reply~~

I'd upgrade my NI 845x to v2.1.2, and I'll try to use basic read/ write later.

Tthe program first coded 3 years ago with NI USB-8451 (max 250kHz).

At that time, I remember basic read and basic write act not exactly follow the script I wrote,

so my slave device (Analog Device AD9888) did not work with NI 845x basic read/ write VIs...