Omega Vehicle Security freedom OM-550 - Manual (Page 31)

OM-550 u 26 u
4.5 MATH PSEUDO-CHANNEL
The OM-550 has five physical channels and a sixth "channel" that can display the
result of a math operation involving any two of the other channels (or a single channel,
twice). The channels chosen as a basis for the Math channel are its "constituents".
The Math channel can be activated or "skipped" during programming. Math channel
data will be printed only (not stored to RAM) if it and both constituent channels are
active (not skipped). If the Math channel is active, its data will be printed (and included
in the "run statistics") with data from the other channels, as channel #6 (refer to section
2.4.2 STATISTICS).
To inhibit the Math channel, program it as Skipped or program it as the combination of
at least one other Skipped channel.
The Math channel can be used to multiply another channel by a constant or add a
constant to another channel. For example, if channel 1 is a Type K Temperature
channel and the user wants to log CH 6=CH 1+10°C, then
•
Program CH 5 as a Voltage channel:
m=0.00000, b=000100, dp=1, units=00
•
Program CH 6 as CH 1+CH 5*
(*Other math functions can be used for desired results).
Now channel 5 will always be logged as 0010.0, regardless of the actual input voltage,
and channel 6 will be logged as CH 1+10. Refer to section 4.14.4 DATA SCALING (mX
+ b calculation) for more information about m and b.
The format rules for printing Math channel data are the same as for other channels; a
"******" will be printed if the value exceeds the available space or the decimal position
selected during programming. Refer to section 4.2 PRINT FORMATTING for more
information.
Although Math channel data may be calculated and printed, it is not actually stored in
the cache memory. When the cached data is transferred to a PC, the software
recreates the Math channel data as necessary. This has one limitation: only one cache-
full of data can be sent to the PC. If more data than will fit in the cache is logged, then
the oldest data is lost and the Math channel statistics (printed on STOP) will be based
on data unavailable to the PC. If this is a problem, program the OM-550 to stop logging
when the cache is full.