Implementation Of PSI-5 Serial Sensor Interface on ADwin Real-Time Data Acquisition Systems
CHESTERLAND OH - The PSI-5 communications interface is a 2 wire serial communications interface which is used to interface sensors to Electronic Control Units (ECU) in applications such as accelerometers for airbag systems. Promoted by major auto suppliers such as Bosch and Continental, the PSI-5 interface has been in use for more than 10 years and has shown itself to be both robust and reliable.
A pressure sensor manufacturer was looking for a system to simultaneously test multiple sensors using this interface. Rather than try to build a custom solution around the dedicated interface chips, they were looking for an off-the-shelf data acquisition solution that could be programmed to read the raw signal and extract the data. For this project, an ADwin-Light-16 Real-Time Data Acquisition System was selected. A simple comparator circuit was used to convert the current signal to a digital waveform that could be read with standard TTL logic. The ADwin system featured 6 high speed digital inputs allowing up to 6 sensors to be read at the same time. For each digital input, a simple state machine was implemented in software to monitor the incoming data, look for the start bits, read and decode the data.
For this project, it was quite straightforward to create a simple state machine using the CASE structure available in the ADBasic programming environment. The deterministic, real-time capability of the ADwin system allowed the data to be read reliably without the need for specialized receiver IC's, and the flexibility of the software enabled the different scenarios and failures mechanisms to be tested quickly and easily.
For further information on ADwin real-time data acquisition and control systems, other data acquisition system product lines, or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Applications Analyst at (800) 956-4437 or visit the website at www.DataLoggerInc.com.
Contact Information:
CAS DataLoggers, Inc.
12628 Chillicothe Road
Chesterland, Ohio 44026
(440) 729-2570
(800) 956-4437
sales@dataloggerinc.com
http://www.dataloggerinc.com
