Omega Vehicle Security manual Detailed description of RS-232 commands, HHTFO101

HHTFO101	Description
b	Return enclosure temperature
f[j]	Set point adjustment to [j]
h	Help menu (this screen)
i	Get factory and status information
q	Scanning rate (q+ for fast/quick, q- for slow)
t	Get Temperature reading channel
ta[i]	Auto temperature output to serial port (+ to enable, - to disable)
u[i]	Unit (c = oCelcius, f = oFahrenheit)
y	Probe power

6.3 Detailed description of RS-232 commands

All commands must be terminated by a carriage return character ( E ). When more than one argument is

required, each argument must be separated from the next one by a blank or space character. Characters are not echoed back to your controlling device.

Every time a command is executed successfully by the thermometer, the “*” prompt character is automatically sent, except in case of failures when the “Errx” error code is sent instead. Do not send your next command before receiving either the “*” or the “Errx” prompt. The “[“ and “]” characters must not be typed in; they are used here for ease of reading only.

“b” This command returns the internal temperature of the enclosure. The temperature is returned in oC or oF unit, as specified by the “u” command.

Ex: “b:32.2 E“

“f[j]” or “f[i j]” This command forces an actual temperature reading (j) for channel # i; any resulting offset will be applied to all future measurements for that channel. This is useful to compensate for small temperature deviations that may occur between sensors. A maximum offset of +/-5oC is recommended; if it is required for you to force a larger offset, your thermometer probably requires a new factory calibration; consult your distributor or factory for more information. This command alters the internal calibration of the instrument. Always follow the recommended procedure, as given below.

Force temperature procedure:

I.Apply a stable and known temperature to the sensor tip

II.Check the display reading for abnormal deviation from the known temperature

III.Send the “f” command followed by channel number, a blank character and the reference temperature value (example “f2 27.0 E“). Temperatures must be entered in units as

	specified by the “u” command
IV.	Wait a few seconds

V.Confirm that the readings correspond to the known temperature.

Note: You can revert at any time to the factory calibration using the “f” (or “f[i]”) command (ex: “f2 E”).

Note: Always make sure you are reading a valid temperature value before using the “f “ command; otherwise, your thermometer may display a random value for a channel where the “f” command has been used.

“h” Displays a help menu screen (see above).

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