Laser beta lasermike LS8000-3 - Manual (Page 38)

LaserSpeed 8000-3 Instruction Handbook
Interfacing with the LS8000-3
Part No. 93463 / Drawing No. 0921-01561 Page 38 of 221 Revision A (Sep 2007)
User Scaleable Pulse Output (Pins 15, 4, 6, 8)
This pulse output is a user-defined 5-24V voltage output with output rates up
to 250 kHz. The output voltage is derived from the User V
IN
input. The pulse
outputs are opto-isolated signals with a voltage level determined by the
voltage supplied on Pin 20 (referenced to User-Ground (pin 11, 19, or 21.) An
isolated TTL level signal (3.7-5V) will be supplied if no external voltage is
connected. The output drivers can handle from 5 to 24 VDC. The external
supply requirements are 5–24 volts DC at 300 mA.
The Low Speed Pulse Output can be reconfigured to output several different
status outputs using the Low Speed Pulse Output Configuration setting.
See the
Configuration Settings section for details.
Differential vs. Single Ended Pulse Outputs
The LS8000-3 Pulse Outputs are available as both differential and single-
ended outputs. Using a counter with differential inputs will provide the best
noise immunity, so Beta LaserMike recommends that the outputs are used in
this configuration.
Unfortunately, many counters do not have differential inputs. The pulse
outputs can be used as single ended inputs by connecting Phase A True and
Phase B True to the counter inputs, and connecting the counter ground to
User Ground (pins 11, 19, 21). Leave the Phase A False and Phase B False
outputs unconnected when connecting for single ended output. If extra counts
occur when the line is not moving, or when the LS8000-3 is powered down,
then noise is getting into the cable and triggering the counter. In this case,
using a conversion circuit to convert from differential to single ended outputs
may correct the problem.