Campbell Scientific SDM-INT8 8-Channel Interval Timer - Manual (Page 17)

SDM-INT8 8 Channel Interval Timer
connected to the datalogger must have a unique address. See Appendix A for
details on changing the address.
6.2 Input Configuration
Each of the 8 input channels can be configured for either high level or low
level voltage input, and for rising or a falling edge detect (see Figure 2). One
digit (0,1,2, or 3) is specified to configure each channel, as shown below.
0 = high level, rising edge
1 = high level, falling edge
2 = low level, rising
3 = low level, falling
Example:
Channel 1 thru 5: high level, rising edge
Channel 6: high level, falling edge
Channel 7 and 8: low level, rising
02:2210 (channels 8,7,6,5)
03:0000 (channels 4,3,2,1)
6.3 Functions
Each of the 8 channels can be programmed independently for various timing
functions. Channel functions are programmed with one digit (0,1,2,3,4,5,6,7,
or 8) for each channel. Functions 0 through 8 are described below.
0 - no value
1 - Period (ms)--
The time between signal edges on this channel in milliseconds.
2 - Frequency (kHz)--
The frequency of signal edges on this channel in kHz. Frequency is
calculated from a measurement of period.
3 - Time since previous channel (ms)--
The time between the signal edge on the next lower numbered channel
and the signal edge on this channel is in milliseconds. This function can
be used to measure pulse width by connecting the signal to two adjacent
channels programmed with opposite edge detect directions.
4 - Time since channel 1 (ms)--
The time between the signal edge on channel 1 and signal edge on this
channel is in milliseconds.
5 - Count on channel 2 since channel 1--
The number of signal edges on channel 2 between channel 1's signal edge
and this channel's signal edge. Linear interpolation is used to derive a
fraction of a count at both the beginning and end of counting
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