HT8100
EN - 10
4.3.7. Output DC current generation
The “OUTPUT” section of the function selector switch defines the possibility of generating
an output DC current with the instrument, considering the selectable measuring ranges
0-
20mA
or
4-20mA
. The instrument may operate in the following modes:
DC current source
DC current generation (see § 4.4.7).
Simulation
simulation of a transducer in a current loop with auxiliary power supply
(see § 4.4.8)
The positions of the rotary switch are the following:
mA
Output DC current, which may be selected as indicated in Table 2
Percentage value (% STEP)
Range 0-20mA
Range 4-20mA
0% 0mA
4mA
25% 5mA
8mA
50% 10mA
12mA
75% 15mA
16mA
100% 20mA
20mA
120% 24mA
Not
available
125% Not
available
24mA
Table 2: Selectable values of output DC current
Output current adjustment is possible with the options:
%STEP
setting of values 0%, 25%, 50%, 75%, 100%, 120%, 125% of the selected
range.
Quick adjustment
setting of values 0%, 50%, 100% of the selected range.
FINE
setting of custom values in the range 0 ÷ 24mA with resolution of 1µA.
mA
Output DC current with automatic ramp as indicated in Table 3
Ramp type
Description
Action
Slow linear ramp
Passage from 0%
100%
0% in 40s
Quick linear ramp
Passage from 0%
100%
0% in 20s
Slow step ramp
0%
100%
0% with ramps of 15s
Quick step ramp
0%
100%
0% with ramps of 5s
Table 3: List of available ramps for output current
4.3.8. Loop Power and HART 250
modes
In the
LOOP POWER
function, the instrument is capable of generating an output voltage >
24V DC to supply an external transducer and directly measure the corresponding loop
current.
The
HART 250
function allows setting a 250
internal resistor for loop measurement on
transducers operating with HART
(Highway Addressable Remote Transducer) protocol.
