Operator`s manual

9-1
SECTION 9. INPUT/OUTPUT INSTRUCTIONS
TABLE 9-1. Input Voltage Ranges and Codes
Range Code Full Scale Range
Resolution
*
Slow Fast
16.67ms 250µs
Integ. Integ.
111 ±5 millivolts 0.33 microvolts
212 ±15 millivolts 1. microvolts
313 ±50 millivolts 3.33 microvolts
414 ±500 millivolts 33.3 microvolts
5** 15** ±5000 millivolts 333. microvolts
*
Differential measurement; resolution for single-ended measurement is twice value shown.
** The Integration times for ranges 5 and 15 are 1.67ms and 25µs respectively.
NOTE: When a voltage input exceeds the range programmed, the value which is
stored is set to the maximum negative number and displayed as -99999 in high
resolution or -6999 in low resolution.
*** 1 SINGLE-ENDED VOLTS ***
FUNCTION
This instruction is used to measure voltage at a
single- ended input with respect to ground.
Standard Output (multiplier = 1, offset = 0) is in
millivolts.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 2 Range code
03: 2 Channel number for first
measurement
04: 4 Input location for first
measurement
05: FP Multiplier
06: FP Offset
Input locations altered: 1 per measurement
*** 2 DIFFERENTIAL VOLTS ***
FUNCTION
This instruction reads the voltage difference
between the high and low inputs of a differential
channel. Table 9-1 contains all valid voltage
ranges and their codes. Both the high and low
inputs must be within ±5V of the 21X's ground
(see Common Mode Range in Section 13.2).
Pyranometer and thermopile sensors require a
jumper between LOW and GROUND to keep
them in Common Mode Range. Standard
Output (multiplier =1, offset =0) is in millivolts.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions
02: 2 Range code
03: 2 Channel number for first
measurement
04: 4 Input location for first
measurement
05: FP Multiplier
06: FP Offset
Input locations altered: 1 per measurement
*** 3 PULSE COUNT ***
There are three pulse input types which may be
measured with the Pulse Count Instruction.
HIGH FREQUENCY PULSE
In this configuration, the minimum
detectable pulse width is 2 microseconds
i.e. the maximum frequency is 250 kHz with
a 50% duty cycle. The 8 bit counter has a
maximum input frequency of 2550 Hz and
the 16 bit option a maximum of 250 kHz.