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Sensoray 518 User Manual

Page 18

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17

Declare Channel Sensor

This command declares the type of sensor connected to a channel. Typically, this command is
executed once for each channel during the coprocessor initialization sequence (i.e., after a reset).
Each execution of this command specifies the sensor type for a single channel, therefore, eight
invocations must occur to declare all eight channel sensors.

A two-byte sequence forms the command string. The first command byte contains the Define
Channel Sensor opcode and desired channel number. The second command byte contains a
“sensor definition code”. Each sensor type is assigned a unique 8-bit sensor definition code.
Refer to the Sensor Tables section for a complete list of sensor codes.

Undeclared channel sensor types default to the 5 volt input range. Any attempt to declare a
“reserved for future use” sensor type will also result in the default sensor type. Declaring a
sensor type as “Disabled” inhibits scanning of the corresponding channel, resulting in increased
throughput for all remaining active channels.

COMMAND: (16 + CHAN), (SENSOR DEFINITION CODE)

RESPONSE: NONE

EXAMPLE:

‘ Configure channel 2 for interface to type K thermocouple.

Channel% = 2 Opcode% = 16 ‘DEFINE CHANNEL SENSOR command opcode
SensorCode% = 3 ‘K thermocouple sensor definition code (from table)

CALL Send518Byte (BasePort%, Channel% + Opcode%)
CALL Send518Byte (BasePort%, SensorCode%)