Campbell Scientific AM16/32A Multiplexer - Manual (Page 18)

AM16/32A Relay Analog Multiplexer
Example: 2 sensors per SET, 6 sensors total; two reps specified in
measurement instruction; two measurement values assigned to indexed input
locations (--); P90 step of 2. Loop count of three.
Input locations
1 2 3 4 5 6
First pass: 1 2
Second pass: 3 4 sensor
Third pass: 5 6 numbers
Removing the step loop instruction from the program, the following situation
results:
Input Locations
1 2 3 4 5 6
First pass: 1 2
Second pass: 3 4 sensor
Third pass: 5 6 numbers
Without P90 the measurement values for the 2nd and 4th sensors will be
overwritten in their input locations. The 1st, 3rd, 5th, and 6th measurement
values will reside in the first 4 input locations.
Step Loop Instruction “90” is available in the CR23X, CR10(X), CR7, and
21X (with 3
rd PROM). For 21X dataloggers without 3 rd PROM (i.e., no
Instruction 90), a separate measurement instruction (with one rep) is required
for each sensor measured within the loop. The input location parameter within
both measurement instructions is indexed.
For example: 2 sensors per SET; one rep in each of two measurement
instructions; two measurement values assigned to indexed input locations (--),
one begins with input location 1, the other with input location 4; no P90. A
total of six sensors to be measured; loop count is three.
Input locations
1 2 3 4 5 6
First pass: 1 2
Second pass: 3 4 sensor
Third pass: 5 6 numbers
A potential drawback of this technique is that sequential sensors (i.e., those
input to the same SET) will not have sequential input locations.
#5 Measure - Enter the instruction needed to measure the sensor(s) (see
Section 6, Sensor Hook-Up & Measurement Examples). The input location
parameter of a measurement instruction is indexed if a (--) appears to the right
of the input location. Index an input location by pressing "C" after keying the
location or by pressing F4 in Edlog while cursor is on the input location
parameter. Indexing causes the input location to be incremented by 1 with
each pass through the loop. This allows the measurement value to be stored in
sequential input locations. Instruction 90, as explained above, allows the
indexed input location to be incremented in integer steps greater than 1.
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