ProSoft ILX56-PBM Integrated Communication Module

ProSoft Technology ControlLogix(1756) backplane PROFIBUS-DP DPV1 master/slave integrated Kommunikationsmodul, designed for Rockwell ControlLogix PLC to interface with PROFIBUS-DP fieldbus devices.

Modelldefinition

ILX56: ProSoft 1756 ControlLogix backplane plug-in module series

PBM: Profibus Master, supports PROFIBUS-DP master mode as well as multi-slave mode

Hardware-Schnittstellen

1. Rückwandplatine: 1756 ControlLogix rack backplane, powered via backplane, besetzt 1 single slot
2. PROFIBUS-DP: DB9-M RS485 connector; Baudrate: full-range support from 9.6 k-12 Mbps
3. Front-panel LEDs: Modulstatus, backplane communication, PROFIBUS bus status indicators
4. Konfiguration: Web configuration + Studio5000 AOP add-on profile; supports FDT/DTM tools for DP slave parameterization and message capture diagnostics

Two Operating Modes

① Master Mode (Commonly Used)

Manages PROFIBUS-DP slaves for connection to DP drives, I/O modules and instruments

Maximum cyclic I/O: 5000 bytes input plus output

Supports DPV0 cyclic I/O; DPV1 acyclic read/write, alarm handling, diagnostics and parameter download

Maximal 125 DP slave stations

② Multi-Slave Mode

The module simulates up to 10 PROFIBUS-DP slave nodes

Maximum 244-byte I/O per virtual slave; total I/O up to 2440 Bytes

Enables ControlLogix to act as a DP slave to connect to third-party PROFIBUS master systems (z.B. Siemens-SPS)

Wichtige technische Spezifikationen

Typische Anwendungsszenarien

1. ControlLogix retrofitting to legacy PROFIBUS-DP drives, instruments and distributed I/O
2. Bus bridging between Siemens DP systems and Rockwell ControlLogix (module operates as DP slave)
3. Projects requiring DPV1 alarms, acyclic parameter access and DTM-based device asset management
4. Plant modernization: retain existing PROFIBUS hardware while upgrading to ControlLogix control system

Kompatibilität & Alternativen

1. In-series Comparison

ILX56-PBS: DP-slave-only version, cannot operate as master; ILX56-PBM integrates master-slave functionality and is preferred for most selections.

2. Alternative Optionen

ProSoft Gateway: PLX31-PBM (stand-alone external gateway, communicates with ControlLogix over Ethernet, no rack slot occupation)

Third-party DP gateways: Domestic PROFIBUS-DP to EtherNet/IP gateways (backplane-mounted or external)

Notiz: Rockwell Automation does not offer native PROFIBUS-DP backplane modules. This third-party ProSoft module is the mainstream choice for 1756 Gestelle.

Pre-owned / Used Module Inspection Checklist

1. Inspect DB9 connector for pin oxidation and bent pins
2. Power-on LED verification: backplane communication LED and DP bus LED status
3. Flash firmware and record firmware revision; verify rack recognition via Studio5000 with AOP installed
4. PROFIBUS bus practical test: connect DP slave, validate master-mode I/O exchange and DPV1 alarm reception

Documentation Resources

User Manual ILX56_PBM_UM.pdf, Datasheet ILX56_PBM_DS.pdf (available for download on ProSoft official website), covering wiring, troubleshooting and DTM configuration procedures.

PROFIBUS-DP Slaves Supported by ILX56-PBM

Protocol foundation: In master mode, the module works with all standard-compliant PROFIBUS-DP DPV0, DPV1 slave devices. Configure slaves by importing the corresponding GSD files. Maximal 125 DP slaves with aggregate cyclic I/O limited to 5000 bytes. Supports Sync, Freeze, DPV1 Class1/Class2 acyclic access, DPV1 alarms and standard slave diagnostics.

1. Classification by Protocol Revision
2. DPV0 Slaves (Basic Cyclic I/O)

Only cyclic process-data exchange without DPV1 acyclic services or alarms. Typical for legacy remote I/O and older-generation drives. Fully supported for cyclic input/output only.

2. DPV1 Slaves (Empfohlen)

Support acyclic read/write, alarm reporting and device parameter download/upload; typical for valve positioners, smart transmitters, modern drives and DP-PA links. The module supports DPV1 Class1(MS1) and Class2(MS2 multi-master) services. Device parameterization and asset management can be performed via DTM inside an FDT framework.

⚠️ Legacy PROFIBUS-FMS devices are not supported. PROFIBUS-PA instruments cannot connect directly. A DP/PA coupler or DP-PA Link must be deployed as a DP slave, with PA instruments connected underneath the link.

2. Common Field-device Types
3. Distributed Remote I/O Modules

Siemens ET200M/ET200S/ET200SP; Wago 750-3xx series; Phoenix Contact Axioline; Beckhoff BK3100; domestic DP remote-I/O units.

2. Variable-Frequency Drives & Sanftstarter

Siemens G120, MM440; NÄHEN; ABB (FPBA-01 DP option card); Schneider ATV series; Rockwell PowerFlex (DP communication option card).

DPV1 enables direct fault-code reading and parameter access; DPV0 only supports setpoint and actual-value cyclic exchange.

3. Servoantriebe

Schneider Lexium; Siemens 611U; SEW servos; third-party servo drives with DP option boards.

4. Pneumatic Valve Islands

Party, SMC PROFIBUS-DP valve manifolds.

5. Process Smart Instruments & Valve Positioners (DPV1 devices)

Siemens SIPART PS2, ABB TZIDC, Fisher DVC6200 valve positioners; PROFIBUS-DP pressure / flow smart transmitters.

6. Third-party PLCs acting as DP slaves

S7-300/400 and other PLCs with DP slave interfaces, connected to ControlLogix as PROFIBUS-DP slaves.

7. DP/PA Link Couplers

Siemens 6GK1412-1DA1 DP-PA Link, operating as DP slave for connecting intrinsically-safe PA field instruments.

3. Software Configuration Prerequisites
4. Use PLX50 Configuration Utility, import manufacturer-supplied GSD/GSDML files, build the DP network configuration and download it to ILX56-PBM.
5. Install AOP in Studio5000; auto-generate ControlLogix tags / UDTs for DP input-output mapping.
6. For DPV1 devices: deploy FDT framework plus device-specific DTM for parameter download and alarm retrieval.
7. Einschränkungen & Wichtige Hinweise
8. Per-slave I/O shall not exceed 244 bytes (hard DP standard limit); total I/O of all slaves shall stay below 5000 bytes.
9. GSD files must match exact device model and revision; mismatched GSD causes misaligned I/O data and communication faults.
10. Non-standard legacy DP slaves not complying with EN50170 may present compatibility issues.
11. The module’s Multi-Slave mode lets ILX56-PBM simulate up to 10 DP slaves so external DP masters can access ControlLogix. This mode is NOT for connecting external DP slave devices. Avoid mode confusion.

External PROFIBUS-DP Masters Compatible with ILX56-PBM

Voraussetzung: set module to Multi-Slave Mode. Under this mode ILX56-PBM simulates up to 10 DP slave nodes, polled by an external DP master.

Protokollkompatibilität: supports standard PROFIBUS-DP DPV0 / DPV1 Class1(DPM1) masters; supports DPV1 acyclic read/write and alarm reporting. PROFIBUS-FMS masters are unsupported.

1. Supported DP Master Device Categories

1.1 Siemens PLCs (Most Common in Field)

S7-300: DP-integrated CPUs (315-2DP, 317-2DP etc.)

S7-400 / S7-400H redundant systems (DP master)

S7-1200 fitted with CM1243-5 DP master module

S7-1500 fitted with CM1542-5 DP master module

ET200SP-CPU (DP master capability)

Configuration note: import ILX56-PBM GSD file in STEP7 / TIA-Portal, configure maximum 10 virtual slave nodes. Match baud rate (9.6 k-12 Mbps) with module setting.

1.2 Third-party PLCs with DP Master Interface

Schneider: Quantum with DP master module, Premium DP master

ABB AC500 series (DP master communication card)

Beckhoff CX-series PLC (PROFIBUS-DP master)

Domestic PLC: Innovation, HollySys and other models with standard DP master interface

1.3 DP Gateways / Couplers Configured as DP Master

Various Ethernet-to-PROFIBUS-DP master gateways (z.B. ProSoft PLX31-PBM, domestic EtherNet/IP-to-DP master gateways)

Wichtig: must be a genuine DPM1 master. Gateways operating only as DP slaves will not work.

1.4 DCS DP Master Systems

Siemens PCS7 (S7-400 DP master)

Other DCS DP master cards complying with DPV0/DPV1 standards

2. Protocol Capabilities under Multi-Slave Mode
3. DPV0: cyclic I/O communication. Each virtual slave max 244-byte I/O; aggregate 2440-byte I/O for ten virtual slaves.
4. DPV1 Class1 (DPM1): external master can execute acyclic read-write and receive DPV1 alarms generated by ILX56-PBM.
5. DPV1 Class2(DPM2) is unsupported: external Class2 diagnostic tools cannot access the module’s virtual slaves; only DPM1 masters are functional.
6. Multi-master token mode is unsupported: only one DPM1 master is allowed on a single PROFIBUS-DP bus segment.
7. Key Limitations & Warnungen
8. The external DP master must import the official ILX56-PBM GSD file. GSD version mismatch produces misaligned I/O and diagnostic faults.
9. Baud rate must match exactly. The module does not support auto-baud-rate detection; baud rate must be pre-configured via PLX50 tool.
10. Only one external DPM1 master per DP bus. When running Multi-Slave mode, ILX56-PBM cannot simultaneously run as DP master; master and multi-slave modes are mutually exclusive.
11. Legacy PROFIBUS-FMS masters are not supported.
12. Redundant DP masters such as S7-400H are compatible, requiring dedicated DP-redundancy configuration.
13. Typische Anwendung

Siemens S7-400 acts as DP master, ILX56-PBM inside ControlLogix runs Multi-Slave mode, realizing Siemens PLC ↔ ControlLogix data exchange over PROFIBUS-DP.

5. Distinguish Two Operating Modes

ILX56-PBM Master Mode: module itself acts as DP master to poll external DP slave devices.

ILX56-PBM Multi-Slave Mode: external DP masters poll this module, ControlLogix behaves as slave on PROFIBUS-DP network.

Upon request I can provide:

1. Step-by-step guide for configuring ILX56-PBM virtual slaves in TIA Portal on external masters;
2. Troubleshooting list for Multi-Slave-mode common faults.

ILX56-PBM and Industrial Ethernet Masters

Critical hardware fact: ILX56-PBM has no physical RJ45 Ethernet port. It implements no native industrial-Ethernet protocol stacks (PROFINET, EtherNet/IP, Modbus-TCP etc.).

All data exchange with higher-level systems takes place over the 1756 ControlLogix backplane CIP bus. The only external fieldbus port is DB9-RS485 for PROFIBUS-DP.

1. Backplane Side (Inside ControlLogix Rack)

ILX56-PBM behaves as a CIP slave I/O module on the backplane.

Backplane master: ControlLogix CPU (1756-L7x / L8x etc.) operates as CIP master, accessing ILX56-PBM for PROFIBUS I/O, diagnostic and alarm data via backplane.

External Ethernet masters cannot access ILX56-PBM directly. All Ethernet traffic must first reach the ControlLogix CPU and then be relayed across the backplane to ILX56-PBM.

In plain words: Ethernet masters communicate only with the Rockwell CPU, they cannot read/write the ProSoft module directly.

2. External Industrial-Ethernet Masters (PROFINET / EtherNet/IP / Modbus-TCP)

✅ Indirect data exchange is achievable (not native direct support)

External industrial-Ethernet masters (Siemens S7-1500 PN, third-party PROFINET controllers, EtherNet/IP masters, Modbus-TCP masters) cannot communicate directly with ILX56-PBM. The mandatory path is:

`External Ethernet Master ↔(Industrielles Ethernet)↔ ControlLogix CPU ↔(1756 Backplane CIP)↔ ILX56-PBM ↔(RS485-DP)↔ PROFIBUS-DP Field Devices`

Common External Ethernet Master Types (Indirect Interoperability)

1. PROFINET Controllers (S7-1200/1500, ET200SP-CPU)

Siemens controller runs as PROFINET master, executes cross-PLC data exchange with ControlLogix over PN-EIP communication. ControlLogix then accesses PROFIBUS data via ILX56-PBM.

ILX56-PBM does not understand PROFINET; protocol translation is performed entirely by the Rockwell CPU.

2. EtherNet/IP Masters

Other Rockwell controllers and third-party EtherNet/IP masters communicate only with ControlLogix CPU, not directly with ILX56-PBM.

3. Modbus-TCP Masters (DCS, Smart Instruments, Third-party PLC)

Additional Modbus-TCP communication module (z.B. 1756-MBTCP) must be installed in ControlLogix rack for CPU-driven data forwarding.

❌ Functions NOT Natively Supported

Cannot operate as PROFINET slave; cannot be scanned by PROFINET masters directly

No external EtherNet/IP slave capability (EtherNet/IP is only used internally between backplane and ControlLogix CPU)

No Modbus-TCP, OPC-UA or other Ethernet protocol processing

Notiz: No embedded Web server. Web-based configuration belongs to other ProSoft models fitted with Ethernet ports; ILX56-PBM has no web interface.

3. Solutions for Direct PROFIBUS-DP ↔ Industrial-Ethernet Master Interconnection

Two main selection paths:

1. Stand-alone Gateway (PLX31-PBM): ProSoft external gateway with PROFIBUS-DP and RJ45 Ethernet port. Can be accessed directly by PROFINET / EtherNet/IP / Modbus-TCP masters, consumes no ControlLogix rack slots.
2. Backplane-module architecture: ILX56-PBM (DP only) plus separate Ethernet communication module in the same 1756 Gestell, relying on CPU for protocol conversion.
3. Model Comparison for Avoiding Confusion

5. Zusammenfassung
6. ILX56-PBM supports master/slave operation only on the PROFIBUS-DP side. It has no built-in Ethernet protocol processing.
7. All industrial-Ethernet masters must go through ControlLogix CPU for indirect access to PROFIBUS-DP data.
8. If the project requires Ethernet masters to read PROFIBUS devices directly, prioritize the external PLX31-PBM gateway instead of ILX56-PBM backplane module.