T8 Release Status

Summary

The T8 is in an early release state. Please keep this in mind before ordering. T8 firmware and LJM support are currently in beta. Below are the support resources necessary to use the T8 with LJM. T8 specifications will be added to the T-series datasheet as they are defined. Known firmware issues are described on the T8 Firmware page.

T8 Limitations

There are some unique limitations to the T8 when compared to our other devices. Please note these limitations before purchase.

• Limitations with Streaming Data Rates:
  Sampling any AIN channel on the T8 using stream mode acquisition will return the simultaneously sampled data for all 8 AIN channels. When streaming at 40 kHz with 8 channels of data being read, the T8 will need to transfer 960+ kilobytes per second to avoid a stream buffer overflow. As such, high stream rates are only possible when certain communication requirements are met.
  High stream rates cannot be used reliably under any of the following conditions:
  
  • When there is a WiFi hop in the Ethernet network.
  • When the connection crosses subnets.
  • If there are any other network conditions that can cause long round trip times.
  High stream rates can be used reliably under either of the following conditions:
  
  • When using a fully wired Ethernet connection from T8 to a switch and/or a computer.
  • When using a USB 3.0 port connected through a powered hub.

• Power Requirements.
  The T8 requires more power than previous LabJack devices and is therefore more sensitive to the quality of the power supply and any USB cable used. Inadequate device power can cause issues with T8 operation. When using USB, we recommend powering the T8 with a wall-powered USB hub.

• The first ~3 AIN stream samples return invalid data.
  It takes ~3 samples for the T8 ADC filter system to start working properly after starting stream. The only recourse is to discard the first couple of readings. We will be investigating ways to reduce the impact of this limitation.

• TEMPERATURE#(0:8) registers do not return valid results when sampling at rates faster than 250Hz (register behavior changed in 1.0004):
  The 250 Hz limit is a hardware limitation. As of firmware 1.0004, the TEMPERATURE#(0:8) registers will return -9999 when the sampling rate is higher than 250 Hz. This is in contrast to earlier firmware versions, which simply return an incorrect value.

• While streaming, temperature and AIN registers cannot be read outside of stream:
  This is a limitation of the stream/AIN timing system. The temperature register readings make use of the analog input system. Temperature sensor readings are acquired simultaneously whenever the AIN are sampled and vise-versa. Stream uses the AIN clock system, resulting in erroneous measurements when reading AIN outside of stream. We will most likely resolve this problem by adding better error handling such that trying to read the AIN or temperature registers outside of stream will cause an error.

• The T8 analog inputs cannot be read (via command-response) when a stream output operation is in progress.

Quickstart

We recommend all new customers go through our T8 Quickstart Tutorial.

LJM Installers

Firmware

See the T8 Firmware page.