PD 621 Application Note - Overview

Feature overview

The PD 621 contains 6 channels, each of which can be independently configured as a digital input or a digital output.
Because of local intelligence within the PD 621, each input or output channel offers advanced functionality. These functions are integrated into the module itself and only need to be configured for operation, and no additional programming is needed. In fact, these unique functions can save a great deal of programming effort.
Since the functions and safety monitors are embedded in the module, they execute independently of external controllers. This ensures safety, ultra fast response and independence from system reaction time.

All PROCES-DATA modules are based on the channel concept. A channel is a functional object, consisting of both functions and all function related data.

A PD 621 Module consists of 2 channel types.

System channel: 
Digital I/O:

Definition of general module behaviour and interface
Definition of function and data for combined digital and analogue input and output

Digital Input Channel modes

– Input mode

Digital Input Channel monitors

– Input cycle counter / counter channel
– Accumulated input active time
– Alarming
– Notification
– Input simulation 
– System Watchdog

Digital Output Channel modes:

– Output mode (traditional output function)
– Toggle mode
– One Shot mode
– Follow mode
– Duty-Cycle mode

Digital Output Channel monitors:

– Output current, Minimum current, Maximum current, Start current grace time,  Overload protection
– Output status feedback
– Output cycle counter, Accumulated output active time
– Alarming
– Notification
– System Watchdog

Application examples PD 621:

Normal output mode with current monitoring:

– Automatic door control
– Detecting blown bulb
– Detecting wire broken

One shot:

– Dosing by fixed time base
– Dosing by adjustable time base

Toggle Applications:

– Room light control

Duty cycle Applications:

– Room temperature control
– Dosing by pulsing

Electrical installation notes:

– Wiring notes for digital output channels
– Wiring notes for digital input channels
– Integrated relay outputs
– External fuse
– Installation according to  – Functional Safety Regulations

Related topics:

PD 620 Digital Input / analogue voltage input
PD 622 Digital Input module