PNI Legacy Comm Board - Manual (Page 30)

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Page 30 of 42
SPI Hardware Handshaking Line Descriptions
SYNC
SYNC is usually low. SYNC must be toggled from low-high-low. This is the SPI reset. This line is used to reset
the SPI slave when communications get out of synchronization. SYNC is normally used during the module
startup.
DRDY – Data Ready
The module returns DRDY. DRDY is low after a SYNC. Once a command has been received and the data is read,
DRDY goes high. This is only used with modules that do not have processor.
NOTE:
See the applicable PNI module data sheet for specific information on communication and control using
the SPI interface
CommBoard
SPI Interface to Sensor Module