AMETEK 1986XPJ Explosion Proof Resolver - Manual (Page 6)

6 1080 N. Crooks Road • Clawson, MI 48017 • 800.635.0289 • 248.435.0700 • Fax 248.435.8120 • www.ametekapt.com
AUTOMATION & PROCESS
TECHNOLOGIES
Variable Pulse (PWM)
The variable pulse signal interface is a pulse
width modulated signal (RS422). The maximum
cable length for the differential LDT is 1,500 feet.
The LDT can also be configured for external or
internal interrogation. External interrogating is
when an external device connected to the LDT
generates a start pulse. This start pulse should be
a minimum of 1.0 microsecond in duration. Within
50 nanoseconds after the leading edge of the start
pulse has been received, the LDT will generate
an output pulse. The duration of the output pulse
is proportional to the distance from the magnet
to the hex head. The order of these two pulses
is illustrated below. The LDT can also generate
internal interrogations. This LDT will continually
output pulse width modulated signals. As with an
LDT using an external interrogation, the duration of
this output pulse is proportional to the distance from
the magnet to the hex head.
OUTPUT PULSE
LOW OUTPUT VARIES DEPENDING ON LENGTH
PROGRAMMED VIA DIP SW2 SWITCHES 1-6
WIDTH OF PULSE IS PROPORTIONAL
TO DISTANCE BETWEEN MAGNET AND HEX HEAD
INTERNAL INTERROGATION
INPUT (INTERROGATION)
1 MICROSECOND (RECOMMENDED)
0.2 MICROSECONDS (MINIMUM)
WIDTH OF PULSE IS PROPORTIONAL TO
DISTANCE BETWEEN MAGNET AND HEX HEAD
OUTPUT PULSE
WITHIN 50 NANOSECONDS AFTER INTERROGATION
TO DISTANCE BETWEEN MAGNET AND HEX HEAD
EXTERNAL INTERROGATION
RS422 Start/Stop with
Interrogation Start Sequence
The start/stop uses a 1 microsecond (minimum)
external interrogation input to start a cycle. Based
on the interogation input, a pair of one microsecond
return pulses are received and the time differential
between the signals is proportional to the distance
from the sensor head (hex) and magnet.
TTL Level Start/Stop Version
The TTL Level start/stop pulse system looks at a
one microsecond TTL pulse (minimum) start pulse
from an external source. The unit will then generate
a TTL level stop pulse. The time span between the
start/stop pulses is proportional to the distance from
the sensor head (hex) to the magnet.
INPUT (INTERROGATION PULSE)
1 MICROSECOND (RECOMMENDED)
0.2 MICROSECONDS (MINIMUM)
TIME BETWEEN PULSES IS PROPORTIONAL TO
DISTANCE BETWEEN MAGNET AND HEX HEAD
OUTPUT (START PULSE) OUTPUT (STOP PULSE)
WITHIN 2.0 MICROSECONDS AFTER INTERROGATION
PULSE BEGINS, START PULSE BEGINS
INPUT (INTERROGATION PULSE)
1 MICROSECOND (RECOMMENDED)
0.2 MICROSECONDS (MINIMUM)
TIME BETWEEN PULSES IS PROPORTIONAL TO
DISTANCE BETWEEN MAGNET AND HEX HEAD
OUTPUT (START PULSE) OUTPUT (STOP PULSE)
WITHIN 2.0 MICROSECONDS AFTER INTERROGATION
PULSE BEGINS, START PULSE BEGINS
Output Types