19 
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 = 
o
Celcius, f = 
o
Fahrenheit) 
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 
o
C or 
o
F 
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 +/-5
o
C 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).