Emerson DL8000 - Pulse Input (PI) Modules

DL8000 Preset Instruction Manual
3-12 Modules Revised February-2016
3.2.8 Pulse Input (PI) Modules
The Pulse Input (PI) module provides two channels for measuring either
a low speed or high speed pulse signal. The PI module processes
signals from pulse-generating devices and provides a calculated rate or
an accumulated total over a configured period. Functions supported are
slow-counter input, slow rate input, fast counter input, and fast rate
input.
The PI is most commonly used to interface to relays or open
collector/open drain type solid-state devices. The Pulse Input can be
used to interface to either self-powered or DL8000-powered devices.
The high speed input supports signals up to 12 KHz while the low speed
input is used on signals less than 125 Hz.
You can configure the PI module as either 12 or 24 Volts dc using
jumper J4 on the module (see Figure 3-10). The PI modules can provide
isolated +12 Volts dc or +24 Volts dc field transmitter power on a per
module basis. For example, one module can provide +12 Volts dc
power, while another module in the same DL8000 controller can
provide +24 Volts dc power. See Figures 3-11 and 3-12.
The PI module provides LEDs that light when each input is active.
Caution
The Pulse Input module only operates with non-powered devices, such
as “dry” relay contacts or isolated solid-state switches. Use of the PI
module with powered devices may cause improper operation or
damage.
The PI modules draw power for the active circuitry from the backplane.
Input signals are optically isolated.
Note: Do not connect wiring to both the Low and High speed
selections for a given channel. Unpredictable operation of the PI
module will result.