Pilz PNOZmulti system extension

Pilz PNOZmulti Configurable Safety Control System: A Complete Guide to System Expansion Planning, Reaction Time Calculation, and Troubleshooting

In modern mechanical safety control, fixed safety relays often fail to meet the requirements of complex applications such as multiple emergency stop zones, actuators with different safety levels, speed monitoring, analog input, and distributed I/O. Pilz's PNOZmulti series configurable safety controllers provide modular and programmable solutions. However, many engineers often encounter issues such as unclear system scalability, excessive response time, and incorrect module configuration during actual project planning, resulting in security features not reaching the required level or responding too slowly.

This article is based on the PNOZmulti system expansion manual (document 1002217-EN-19), which systematically outlines the maximum expansion configuration, expansion module types, and left and right slot allocation rules for three platforms - PNOZmulti Classic, PNOZmulti Mini, and PNOZmulti 2. More importantly, we will provide a detailed interpretation of the calculation formula for system response time and guide you in accurately calculating the maximum turn off delay by combining multiple practical configuration cases (input from safety I/O, output to semiconductor or relay contacts, and connecting multiple controllers through Link or SafetyNET p). Finally, practical suggestions are provided for common configuration errors, reasons for exceeding delay limits, and on-site troubleshooting.

Comparison of System Scalability among the Three Major Platforms of PNOZmulti

2.1 PNOZmulti Classic (base PNOZ m0p/m1p/m2p/m3p)

Base type: PNOZ m0p (ETH), m1p (ETH), m2p (ETH), m3p (ETH)

Maximum Expansion:

On the right side of the base: up to 8 expansion modules (input/output/speed monitoring/analog).

On the left side of the base: up to 4 expansion modules (analog input module PNOZ ma1p)+1 fieldbus module.

Link module: Each PNOZ ml1p can connect to 2 bases (for dual controller redundancy or expansion); Each PNOZ ml2p can connect up to 4 distributed modules PDP67 (IP67 safety I/O) and support up to 16 distributed modules (4 link modules x 4).

Common extension modules (right slot):

PNOZ mi1p: 8-way secure input

PNOZ mi2p: 8-channel standard input (non secure)

PNOZ mo1p: 4-channel secure semiconductor output

PNOZ mo2p: 2-channel safety relay output

PNOZ mo3p: 2-channel bipolar safe semiconductor output

PNOZ mo4p: 4-channel safety relay output

PNOZ mo5p: 4-channel diverse redundant relay outputs

PNOZ ms1p~ms4p: Speed monitoring module (1 or 2 axes, supporting proximity switches, incremental encoders Sin/Cos/TTL/HTL)

Note: Different base models support different numbers of modules on the right side. For example, PNOZ m0p does not support right side extensions (0), while m1p/m2p/m3p supports 8. The number of modules on the left side is 4.

2.2 PNOZmulti Mini (base PNOZ mm0p/mm0.1p/mm0.2p)

Maximum Expansion:

On the right side of the base: only one PNOZ sigma expansion module (such as PNOZ s7 relay output)+optional one contact expansion module (such as PNOZ s7.1, which can be connected to an external PNOZ s7/s10/s11 for contact expansion).

On the left side of the base: up to 1 fieldbus module+1 communication module+4 link modules (PNOZ mml2p is used to connect distributed PDP67) → up to 16 distributed modules.

Link module: PNOZ mml1p can connect 2 Mini bases; PNOZ mml2p connects distributed modules.

Common extensions (right slot):

PNOZ s7, s7.1, s7.2, s10, s11: Single channel safety relay output

PNOZ s22: Dual safety relay output

Note: PNOZ mm0p does not support any extensions; Mm0.1p and mm0.2p support the aforementioned Sigma module.

2.3 PNOZmulti 2 (base PNOZ m B0/m B0.1/m B1/m C0)

Maximum Expansion:

On the right side of the base:

PNOZ m B0: up to 6 security extension modules (including input/output/speed monitoring/analog)

PNOZ m B1: up to 12 security extension modules (but the total number of PNOZ m EF 4DI4DOR, 4DI4DORD, and 2MM does not exceed 8); And it supports up to 6 standard (non safety) output modules (such as PNOZ m ES 14DO), which must be placed at the right end of the safety module.

PNOZ m B0.1: Only 1 expansion module

PNOZ m C0: No extension

On the left side of the base: up to 4 expansion modules+1 fieldbus module+1 communication module (applicable to m B0/B1).

Link module: PNOZ m EF Multi Link (connecting two bases); PNOZ m EF PDP Link (connects up to 4 PDP67 distributed modules, up to 16); PNOZ m EF SafetyNET (up to 16 SafetyNET p RTFL stations connected linearly).

Common extensions (right slot):

PNOZ m EF 16DI: 16 secure inputs

PNOZ m EF 8DI4DO: 8-in 4-out semiconductor safety output

PNOZ m EF 4DI4DOR: 4-in 4-out relay safety output

PNOZ m EF 2DOR: 2-channel safety relay output

PNOZ m EF 1MM/2MM: motion monitoring (1 or 2 axes)

PNOZ m ES 14DO: 14 standard semiconductor outputs (only m B1 supports 6)

Calculation of System Reaction Time: Principles and Formulas

The total response time of the safety control system (from input signal change to output cut-off) directly determines the safety distance and risk assessment. The reaction time of PNOZmulti system consists of three parts: