PNI CommBoard User Manual

Page 14

PNI Sensor Corporation

DOC#1018122 r02

PNI CommBoard User Manual

Page 12

– DRDY Hold

This command causes an indefinite delay of processing subsequent characters

received from the host until a „Q‟ character is received or the conditions of DRDY

port pin are met. The syntax is:

such that # is either “1” or “0”, where “1” indicates DRDY must be HIGH to release
the hold and “0” indicates DRDY must be LOW.

Characters received from the host will continue to be stored in a 100-character buffer.
The exceptions are the „Q‟ and „F‟ commands, as they are processed as soon as they
are received. Once the hold condition on the DRDY line is met the system will begin

processing characters in the receive buffer in the order received.

Example: Wn1~1Rsi

Writes 01, then waits for DRDY to go HIGH. When DRDY goes HIGH the

CommBoard then fetches (reads) a signed 16-bit value from the SPI port.

Y or y

– Hold Always

This command causes the indefinite delay of processing subsequent characters

received from the host until a „Q‟ character is received. Characters received from the
UART, other than „Q‟ or „F‟, will be stored in a 100 character buffer. Once a „Q‟ is
received the system will begin processing characters in the receive buffer in the order

received.

Example: YwN1,2RMQ

As soon as the “Y” character is received, the CommBoard will stop processing.

Once the “Q” character is received the CommBoard will write two bytes, 01 and

02, and then receive an unsigned 3-byte word.

– Quit Hold

Note that only capital „Q‟ is recognized. Receipt of this character immediately
releases any hold command presently set. This includes the DRDY Hold or the Hold

Always commands. Characters in the receive buffer will begin processing. If the

desire is to not process the buffer, then the Flush Buffer command should be sent
immediately prior to sending, as “FQ”.

– Flush Buffer

This command flushes the receive buffer. If there is a Hold command presently set

and the buffer contains characters, this command purges the characters in the buffer.