- Topic ID: id_15460448
- Version: 2.0
- Date: Nov 8, 2018 1:39:33 AM
Auxiliary Channel Test
The auxiliary channel test’s primary function is to query the DCB and report specific data-such as detector temperature, power supply voltage, board temperatures, and KV/mA readings. With the exception of the KV/mA channel sub-test, this test uses basic firmware routines to communicate and query the DCB. It does not use the Scan Acquisition process that DDC uses. The reason is that if the DAS fails power-up diagnostics, the error is reported to software and scanning is prevented, either in applications or Diagnostic Data Collection (DDC). This “tool” allows the user to query the DCB and read the supply voltages, or detector board temperatures “real-time”.
The Iterations setting can be changed to poll and report aux channel data over a period of time at defined intervals.
In the log output from this test, ONLY failures are listed. Passing results are not shown. To view all results look at the ssw.dastools_aux_chxx.hist file found in /usr/g/service/state directory, where xx is 01-05 rotating log files for each pass.
1 Detector Rail Temperature
The detector temperature is measured by the DCB as is reported in one of the auxiliary channels. The DCB queries the Heater Controller through the fan controller communication link. The specifications vary depending on the detector type and are reported with the Aux channel output.
2 Power Supply Voltages
DCB circuitry measures all DAS power supplies and reports in the auxiliary channels in the form of voltages. The DCB also queries the DIFB's for the power supply voltages they generate for themselves and the A/D boards of all Digital Modules. The supplies that go to the Digital modules are sampled at the backplane connection for each Digital module's digital cable. The specifications and results are all shown in the Aux channel output.
3 Board Temperatures
The DCB queries the DIFB's to supply the DIFB and Digital module board temperatures. The DIFB's and A/D board's (2 - A/D boards per digital module, each with 2 sensors) temperature is read and reported in the Aux channel output. There are no specifications but the DIFB's will shut down power to the A/D boards should an over temp condition exist. A power or hardware reset is required to restore the DIFB power. Another source of good information is the Scan Analysis Aux channel plotting that will show the temperature profile across the detector for the DIFB's and A/D boards.
4 KV / mA Channels
These auxiliary channels report the actual KV and mA signals as read from the generator (KV and mA control boards). Since this requires x-ray, this test is not part of the auto-mode, but it can be initiated in the manual-test mode with operator intervention. You must push the Scan Enable push-button to initiate x-ray. All x-ray safe guards are in place, which terminate x-ray in the event of a system failure, tube cooling limitations, or exposure time limitations.
The test takes several scans at selected techniques, and the measured KV and mA signals are compared to the selected techniques. If the reported signals do not match the firmware reported technique with specifications then a failure will be noted in the DAStools log. See the gantry interconnect drawing for the kV/mA measured signal path to the DCB which is different depending on system type.