Sensoray 7429 User Manual
Page 25
Set Open Sensor Data Values
This command establishes the data value to be returned for each channel if an open sen-
sor is detected. Depending on the form of the command, either channels 0-7 or 8-15
are affected.
Bits belonging to the second command byte are mapped to channels in the following
way: bit 7 (most significant bit) to channel 7 or 15, bit 6 to channel 6 or 14, etc.
If a bit is set (logic 1) and the corresponding channel sensor is open, one of two data
values will be returned by the read channel data command requesting data for that
channel. If the bit is set (logic 1), the value 32767 will be returned. If the bit is reset,
the value -32768 will be returned.
COMMAND:
(80),(OPEN SENSOR FLAGS — CHANNELS 0-7)
RESPONSE:
NONE
COMMAND:
(81),(OPEN SENSOR FLAGS — CHANNELS 8-15)
RESPONSE:
NONE
Example: An alarm is to sound if the K thermocouple on channel 7 fails. The ther-
mocouple is regulating the temperature of an oven.
Assuming that we don't want the oven temperature to run away as a result of the
sensor failure, the channel should be programmed to fail high so that the controller
will shut off the heating control. This code segment will satisfy these requirements.
OpenFlags% = 128'flags: (1,0,0,0,0,0,0,0)
CALL SendByte (80 + 7)'send opcode + channel
CALL SendByte (OpenFlags%)'send flags