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PD 661 Simple P-NET Interface


General information

The PD 661 Simple P-NET Interface is one of a number of standard modules within the PD 600 series range. Its main purpose is to provide a transparent link between standard RS485 P-NET and the optical Light-Link P-NET used between other PD 600 series modules.

Furthermore, the PD 661 provides a transparent link between Light-Link P-NET and 4-wire P-NET.

The module itself does not require any programming or configuration. This module is normally used either when no DPI is included within a cluster of I/O modules and a connection is required with RS485 P-NET, or a DPI is included, but this has an interface with a standard other than RS 485. The PD 661 device performs a direct (repeater) link between an RS485 network segment and Light-Link, meaning that any modules included in the cluster will be regarded as part of that RS485 network. In other words, no gateway function is involved, as would be the case if the connection were made through a DPI. It is used with a BM 010 Base Module (standard RS 485 P-NET), or with a BM 012 Base Module (4-wire P-NET).


It should be noted, that the highest possible speed on Light-Link is 230400 BAUD, whereas the highest speed on RS 485 is 76800 BAUD. As the PD 661 device performs a direct link between Light-Link and RS 485, the highest possible speed is 76800 BAUD.


PD 661 Block Schematic

The diagram shows connection possibilities for a PD 661



Electrical Specifications


Power supply



Power supply DC:




24.0 V

18.0 V

32.0 V







Power consumption @ 24Vdc





30 mA

Current at power up:


100 mA







EN 61000-6-2, EN 61000-6-3









Test method: IEC 60068-2-6



Frequency range:

2-100 Hz

Frequency / amplitude:

2-10 Hz :     +/- 5.0 mm


10-100 Hz:  +/- 2g

Sweep rate:         

Max. 1 octave/min

Number of axes:

3 mutually perpendicular



Mechanical Details


Related topics

Base module overview

Wiring diagram

LED function

PD 990 4-WIRE P-NET Conditioner

Using PD 661 as replacement for PD 660

Ordering Information