Tamarisk
®
320
Software ICD
8
Note that the bit-wise AND operation ensures the checksum length remains 1 byte.
2.2 COMMAND MESSAGE FORMAT
All commands originate from the connected device and are sent to the thermal imaging module
(TIM). The TIM does not originate commands but it may send occasional text messages.
All commands conform to the general message format. The command byte identifies the specific
command to be performed. Additional data bytes are included in the command as required. Refer
to command details section for specifics.
The module will be ready to accept commands within 2 seconds of power-on.
2.3 RESPONSE MESSAGE FORMAT
All commands sent to the TIM are expected to receive at least one response message (exception:
changing the baudrate command will not produce a response).
In general, systems communicating with the TIM should wait for the response message prior to
subsequent messages being sent.
If the TIM finds a message format error or bad checksum, the TIM will not send a response.
If the message format and checksum is correct, but the command is not recognized, the TIM will
send an Error (ERR) response. The error response may include a descriptive string that describes
the error.
If the received message is properly formatted (including checksum) and the command is
recognized, the TIM will generate an Acknowledgement (ACK) response.
On select commands, the module may send other responses. The type of response depends on the
command that was received. Response types are:
♦
A text message. These are output using the TXT identifier. The text message will
contain the requested information or other feedback (see the individual message
detail) as null-terminated ASCII strings.
♦
A value message. These are output using the VALUE identifier. The value message
includes a 16-bit numerical value.
♦
The original command. The command will contain new parameters that include the
response data.
Table 2 – Response Message Types
Name
Command
ID
Additional data
Text message (TXT)
0x00
Text message (variable # of bytes defined in the
Data Length field)
Note: to receive a text message, the module must
have debug message mode ON.
