User's Manual

© SENSITECH INC. CONFIDENTIAL – CONTROLLED DOCUMENT Page 60 of 83
A Carrier Corp. Company
PART NUMBER T82002163
REV A
CMD_UNKNOWN 0x02 The requested command is not part of the unit's API. This is returned
when a command does not exist. This error code is also returned if a
command that is sent requires a higher access level than the user is
presently in.
BAD_PASSWORD 0x03 During the course of logging into the unit, the supplied password is
incorrect.
BAD_TEMP 0x04 When an immediate temperature is requested, this value will be returned if
the conversion process did not complete successfully.
IIC_TIMEOUT 0x05 During the course of accessing the internally paged memory, either a read
or write time out occurred.
BAD_INIT 0x07 The unit can not be initialized due to erroneous information having been
stored in its configuration pages.
UNIT_NEW 0x0A The unit is newly manufactured and un-configured.
UNIT_SLEEPING 0x0B The unit is sleeping prior to activation.
UNIT_SDELAY 0x0C The unit has been activated and is waiting through the startup delay.
UNIT_RUNNING 0x0D The unit has completed the startup delay and is actively recording data.
UNIT_STOPPED 0x0E The unit has been stopped after running.
Communication Layer Descriptions
The unit utilizes a layered communications protocol. The default layer is no-communications or
Data Recorder mode (unit recording temperature data). The host computer moves from layer 0 to
layer 1 and succeeding layers by successfully sending the appropriate command or sequence of
commands. Presently there are a total of 5 layers. The following table lists the layers by name
and description.
Layer # Layer Name Layer Description
0 Data Recorder No communications - Awaiting communication
initialization sequence.
1 Identification/
Networking
Communications Established – Awaiting unit
identification/networking commands.
2 Login/Status Unit Identified - networking issues handled - awaiting
user login.
3 Customer Login
(password
disabled.)
Logged in Customer privilege - all general user
commands available.
4 Sensitech login
(password req.)
Logged in with Sensitech privilege. All unit commands
available including test and general commands.
Data Recording Layer
There is no way of telling what the unit may be doing when the host computer tries to initiate
communications. It may be recording data in which case communications are disabled. It may be
in sleep mode, in which case waking up can take 500 milliseconds. One last issue that the unit has