Gefran GILOGIK II Distributed I/O System

Gefran GILOGIK II Distributed I/O System

Introduction: When Distributed I/O Becomes an Automation Bottleneck - The Alternative Value of GILOGIK II

In the field of industrial automation, distributed I/O systems play a critical role in connecting on-site sensors, actuators, and central controllers (PLC or IPC). However, many outdated systems, such as early Profibus DP, DeviceNet, or CAN networks, are limited by bandwidth, real-time performance, and scalability, gradually becoming bottlenecks in improving overall line efficiency. When the original fieldbus module is discontinued, communication failures occur frequently, or data refresh cycles cannot meet high-speed applications, engineers urgently need a new generation of distributed I/O architecture with nanosecond level synchronization, microsecond level refresh, modular and flexible expansion.

Gefran GILOGIK II is precisely the solution designed for this purpose. It is based on a 200 MHz ARM processor and parallel backplane bus, and can achieve 100 µ s I/O data refresh and zero jitter (jitter ≈ 0) synchronization performance at a system scale of up to 16 nodes and 256 I/O per node through proprietary GDNET real-time Ethernet protocol. Its modular gateway supports mainstream fieldbuses such as CANopen, DeviceNet, Profibus, and can directly connect to standard Ethernet networks.

This article will provide a detailed analysis of the system architecture, backplane and module installation, gateway configuration, I/O module selection of GILOGIK II from an engineering perspective, as well as replacement methods and troubleshooting strategies for discontinued distributed I/O systems from other brands.

System Overview: Core Competencies of GILOGIK II

2.1 Product positioning

GILOGIK II is a high-performance distributed I/O system suitable for scenarios such as machine automation, process automation, distributed control of large installations, data acquisition, production management, and building automation. Its design philosophy emphasizes:

High performance: 200 MHz ARM processor+parallel backplane bus → extremely short response time

High flexibility: The gateway can be configured with multiple fieldbuses, and I/O modules can be inserted into any slot (geographically addressed)

High reliability: module and on-site isolation, anti-interference; All wiring uses spring terminals without screws

Easy to maintain: Hot swappable module, pluggable wiring terminals, module replacement without rewiring

2.2 Architecture Composition

The entire system consists of the following parts:

Backboard (R-BUS series): Provides 4/8/12/18 slots, and modules are fastened into the backplane through screw free connectors. The backboard can be installed on a 35 mm DIN rail or directly fixed to the base plate.

Gateway node: responsible for communicating with the upper control system (such as PLC, PC, or GT-C human-machine interface) and managing the I/O modules on the backplane. Different gateways correspond to different fieldbus protocols.

I/O module: including specialized modules for digital, analog, temperature control, counting, etc.

Communication Expansion: R-ETH100 (Ethernet interface), R-SW5 (5-port industrial Ethernet switch, used for GDNET star/tree expansion), etc.

Human machine and control unit: GT-C (panel type industrial control computer, running software logic and HMI), GT-O (remote control panel), and GF-BOX (box type industrial control computer).

2.3 Key Performance Indicators

Backplane bus: 16 bit parallel, terminated, geographically addressed, modules do not require continuous insertion.

GDNET protocol: Based on standard Ethernet 100 Mbit/s, dedicated frame structure ensures deterministic transmission.

Refresh time: Single node I/O data refresh ≤ 100 µ s, multi node systems can still maintain a cycle of ≤ 1 ms.

Node capacity: Up to 16 nodes, with a maximum of 256 I/O points per node.

Power supply: The system is powered by a gateway module providing 24 Vdc/3 A power to the backplane, without the need for an additional power module.

Working environment: Operating at 0-50 ℃, stored at -20~70 ℃, humidity ≤ 90% without condensation, protection level IP20 (module body).

Backboard installation and grounding: a reliable starting point for foundation engineering

3.1 Backboard selection

Model, slot number, size (width x height x depth), mm, weight, order number

R-BUS4 4 104 × 110 × 30 120 g F026085

R-BUS8 8 208 × 110 × 30 240 g F026086

R-BUS12 12 size see manual - F026087

R-BUS18 18 size see manual - F026088

3.2 Installation method

Method 1: Install on Ω - shaped guide rail (35 mm)

Warning: It is strictly prohibited to clamp the backplane onto the guide rail while the module is already inserted, otherwise it may damage the module pins.

First fix the Ω guide rail to the bottom plate, then hook the upper teeth (tooth 1) of the back plate onto the edge of the guide rail, and rotate the back plate downwards until the bottom teeth (tooth 3) make a "click" sound to lock.

When disassembling, use a screwdriver or fingers to pull the release lever (lever 4) to disengage the bottom teeth, and then rotate it in the opposite direction to remove it.

Method 2: Directly fix on the base plate

Drill holes on the bottom plate according to the size drawing of the back plate (using M4 screws) and fix them through the mounting holes on the back plate. At this point, the backplane loses its grounding connection with the Ω rail, and an additional grounding bar R-BPE (n) needs to be installed for the module's grounding spring contact.

3.3 Grounding System

Each I/O module has a spring-loaded grounding connector on the back, which automatically contacts the mounting rail (metal Ω bar) or grounding bar when the module is inserted into the backplane. If using direct base plate installation, R-BPE4/8/12/18 grounding copper bars must be equipped. At the same time, the system also provides R-BSCH series shielding bars for centralized grounding of cable shielding layers.

Engineering Tip: Poor grounding can lead to analog signal drift, false triggering of digital signals, and electromagnetic interference (EMI) issues. Be sure to ensure that the Ω rail or grounding bar is connected to the system's main grounding point at a single point.

Gateway module: the core that connects fieldbus and backplane

The gateway module of GILOGIK II is responsible for protocol conversion and I/O management. Different gateways correspond to different upper communication protocols.

4.1 Gateway Types (Partial)

Description of fieldbus supported by gateway models

R-ETH100 GDNET/Ethernet standard Ethernet gateway, used to connect GT-C/GF-BOX or directly serve as a Modbus TCP server

R-SW5-5 Fast Ethernet switch, used for building multi node GDNET networks; Can be used independently as an industrial switch

R-E16 is not clearly defined as a 16 channel expansion gateway (not fully listed in the manual, please consult the manufacturer)

R-U8/R-U16- Universal Gateway, supporting multiple protocol conversions

The gateway module is inserted into the first slot of the backplane (usually the left end) and provides 24 Vdc power (up to 3 A) to the entire backplane. Therefore, the total power consumption of the system cannot exceed the power supply capacity of the gateway. When designing I/O configurations, it is necessary to accumulate the power consumption of all modules to ensure that it does not exceed the limit. If exceeded, modules with external power supply can be selected (some analog output modules support external 24 Vdc power supply).

4.2 GDNET Communication Protocol

GDNET is a real-time deterministic protocol based on Ethernet developed by Gefran, which has the following characteristics:

Low latency: I/O data refresh time is only 100 µ s (single node)

Zero jitter: dedicated hardware synchronization mechanism to ensure accurate arrival time of periodic data

Multi node support: up to 16 nodes, 256 I/O per node

Network topology: Star and tree cascading can be achieved through R-SW5 switches, and the distance between nodes is determined by standard Ethernet specifications (100 m copper cable)

Typical point-to-point application: A GT-C (or GF-BOX+GT-O) is directly connected to a GILOGIK II gateway through a crossover cable for standalone device control. Typical multi-point application: Multiple GILOGIK II nodes are connected to the same GT-C through an R-SW5 switch to form a distributed control system.

4.3 Integration with third-party PLCs

Due to GILOGIK II's gateway supporting standard protocols such as Profibus, DeviceNet, CANopen, etc., it can be used as a slave to access mainstream PLC systems such as Siemens, Rockwell, Schneider, etc. Meanwhile, through the R-ETH100 gateway, it can also serve as a Modbus TCP server and communicate directly with the upper computer SCADA.

Typical scenario for replacing old I/O: When distributed I/O systems that originally used Profibus DP (such as Siemens ET200, Phoenix Inline) need to be replaced due to module discontinuation, GILOGIK II's Profibus gateway can be used to keep the Profibus master station of the upper PLC unchanged and only replace the on-site I/O rack. This greatly reduces the workload and downtime of system renovation.

Detailed explanation and selection comparison of I/O modules

GILOGIK II provides a wide range of digital, analog, and special function modules, all of which have a uniform size of 26 mm wide, 90 mm high, and 120 mm deep. They are IP20 protected and use spring clip terminals for wiring (no screws required).

5.1 Analog output module

Model Output Channel Output Range Resolution Order Number

R-D/A4 4 ±10V / 20 mA max 16 bit F027510

R-D/A8 8 ±10V / 20 mA max 16 bit F027064

R-D/A8VI 8 can be configured with ± 10V/0-20mA/4-20mA 16 bit F028004

R-D/A16 16 ±10V / 20 mA max 16 bit F027065

Key parameters: setup time of 50 µ s, optical isolation, external 24 Vdc power supply (0.5 A max)

Application: valve positioning, frequency converter speed setting, servo torque control

5.2 Analog Input and Temperature Module

Model Type Input Range Resolution Order Number

R-A/D8 8-channel analog input 0-10V, ± 10V, 0-20mA, 4-20mA, 0-2V, etc. 16 bit F027063

R-TC8 8 thermocouple/RTD input+16 digital outputs (for temperature control) J, K, R, S, PT100, 0-50mV, 0-2V, etc. 18 bit min F026944

R-D/A8VI already includes analog outputs

Special features of R-TC8: It has 8 built-in temperature inputs (supporting multiple sensors) and 16 optically isolated digital outputs (0.5 A/channel, maximum 6 A simultaneously), which can directly drive heaters or solid-state relays (SSRs). Additionally, a 24 Vdc PNP digital input is provided for measuring time intervals (such as pulse cycles). This module is very suitable for applications such as multi temperature zone injection molding machines, extruders, hot runners, etc.

5.3 Other modules

Digital module: The manual does not list specific models, but the system supports multiple 8/16 channel digital input/output modules (order numbers can be consulted with Gefran).

R-C3: It may be a counter module (listed only in the model summary table, not detailed).

R-U8/R-U16: Universal module, specific functions to be investigated.

5.4 Module selection and replacement comparison

When modules of old distributed I/O systems (such as Siemens ET200S 4AO module, AB 1794 series analog output, etc.) need to be replaced, the following equivalent comparison (functional equivalence, non pin to pin) can be referred to:

Original brand/model functional description GILOGIK II alternative model

Any 4-channel ± 10V output 4AO, 16 bit R-D/A4

Any 8-channel 4-20mA output 8AO, configurable current/voltage R-D/A8VI

Any 16 channel 0-10V output 16AO R-D/A16

8-channel universal analog input 8AI, multiple ranges R-A/D8

8-way thermocouple input+PID control TC input+digital output R-TC8

Attention should be paid when replacing:

Different wiring terminals: GILOGIK II uses spring terminals, while the original system may have screw terminals or pre wired connections. Need to re crimp the wire or use an adapter.

Bus protocol: If the original PLC master station is retained, the corresponding gateway (such as Profibus gateway) must be selected.

Software configuration: GILOGIK II is fully configured through software (no hardware jumpers required), and I/O parameters and addresses need to be set using the Gefran configuration tool.

Module installation, wiring, and hot plugging

6.1 Module installation and disassembly

Installation: Align the module with the guide rail on the backplane and push it vertically until the two side buckles are locked. When the module is inserted, it will automatically connect to the backplane bus and grounding spring.

Disassembly: Use a straight screwdriver (diameter ≤ 2.5 mm) to insert into the gap between the side of the module and the buckle, pry open the buckle, and pull out the module backwards at the same time.

Important: Before disassembly, disable the module from the software or cut off the system power (depending on the application). Although the system supports hot swapping, suddenly unplugging a module that is communicating may result in bus errors or slave station failures.

6.2 Spring terminal wiring

All wiring terminals of I/O modules are pluggable female heads with spring clips. The wiring steps are as follows:

Insert a screwdriver with a diameter of ≤ 2.5 mm vertically into the square hole above the terminal hole and press down on the spring.

Insert the soft copper wire with stripped insulation layer (hard wire and tin coating are strictly prohibited) into the circular wire hole.

Pull out the screwdriver, and the spring will automatically clamp the wire.

To remove the wire, repeat step 1 and unplug the wire.

Wire cross-section: Select according to the module data manual, typically using 0.5~1.0 mm ² shielded wire for digital signals and 0.25~0.5 mm ² shielded wire for analog signals.

6.3 Wiring precautions

Analog signals should use shielded twisted pair cables, and the shielding layer should be grounded at the module end through a shielding bar (R-BSCH).

The inductive loads (relays, contactor coils) of the digital output module must be connected in parallel with freewheeling diodes or RC absorption circuits to prevent back electromotive force from damaging the output.

The 24 Vdc power supply should be led out from the gateway or external power supply through a fuse, and should not be directly connected to unprotected lines.

Human Machine Interface and Control System: GT-C, GT-O, and GF-BOX

The GILOGIK II system is not only an I/O subsystem, but can also be deeply integrated with Gefran's control panel to form an integrated control solution.

7.1 GT-C: Panel type Industrial Control Computer

GT-C is a high-performance operation panel that integrates software logic control and HMI. Main specifications:

Processor: Celeron 400 MHz/Pentium III 800 MHz/Pentium M 1.1 GHz (optional)

Display screen: 10.4 "or 12.1" TFT, 800 × 600 pixels, wide viewing angle (170 °/170 °), contrast ratio 300:1

Memory: 128 MB SODIMM (expandable to 512 MB), 256 KB battery backed SRAM

Storage: 64 MB DOM (expandable to 756 MB) or 2.5 "IDE hard drive (≥ 20 GB)

Operating System: Windows 98/XP Embedded/VxWorks

I/O custom interface: can connect up to 128 key matrix keyboards and 64 LEDs, and provide one optically isolated 24 Vdc logic output (100 mA, programmable timed start, can be activated even if the system is powered off)

Expansion slots: 1 x PCI, 1 x PC104, 2 x PCMCIA, 3 custom ISA slots, 1 custom PCI slot

Communication: Ethernet (10/100), 2xUSB, 2xCOM, PS/2, VGA, etc

Protection level: IP65 front panel

7.2 GT-O: Remote Control Panel

GT-O is a remote display and operation unit used in conjunction with GT-C or GF-BOX, with a maximum distance of 25 meters through dedicated cables. It does not have a local processor, but serves as a graphics terminal for the host. The keyboard configuration is similar to GT-C (8 function keys, 23 screen management keys, 20 customizable control keys, 49 keys with LED, etc.), the front panel is IP65, and the working temperature is 0-50 ℃.

7.3 GF-BOX: Box type Industrial Control Computer

GF-BOX is an industrial PC suitable for control cabinets, using the same processor and expansion capabilities as GT-C, but without a display screen. It connects to GT-O through a remote VGA interface and can be placed deep in the electrical cabinet, while GT-O is installed on the cabinet door. GF-BOX also has a matrix keyboard/LED control interface and programmable timing output.

Typical combination: GF-BOX+GT-O form a low-cost and highly reliable operation station, used to replace traditional PLC+HMI discrete solutions.

Replacing discontinued distributed I/O systems: steps and precautions

8.1 Evaluate the key parameters of the original system

Before deciding to replace a discontinued distributed I/O (such as ABB S800 I/O, Siemens ET200M, Mitsubishi MELSEC remote I/O) with GILOGIK II, the following information needs to be collected:

Fieldbus protocol: Profibus DP, DeviceNet, CANopen, or proprietary? GILOGIK II gateway needs to be matched.

I/O points and types: List the number of all analog/digital/thermistor/thermocouple/high-speed counting channels.

Power supply method: Is the original system uniformly powered by the gateway? GILOGIK II gateway has a maximum power consumption of 3A. If the total power consumption exceeds this limit, an external power module needs to be added.

Installation space: Does the number of backplate slots meet the requirements? Do you need slots 4/8/12/18?

Wiring terminals: Did the original system use pluggable terminals? The spring terminal of GILOGIK II requires a suitable wire stripping length.

8.2 Hardware replacement steps

Dismantle the old rack: Power off, label all on-site cables, and remove the old I/O module and backplane.

Install new backplate: Choose Ω guide rails or directly fix according to the on-site backplate situation. Be sure to install a grounding system.

Cable arrangement: Reconnect the on-site signal line to the spring terminal module of GILOGIK II. The original cable can be used, but the ends need to be stripped and welded or cold pressed (GILOGIK II requires bare wires and cannot use cold pressed terminals). It is recommended to use R-CON series plug-in connectors for pre installation.

Insert gateway and I/O module: First insert the gateway (usually the first slot from the left), then insert any I/O module. The system supports geographic addressing without the need for sequential order.

Power supply and preliminary testing: After powering on, observe the gateway module LED and check if the backplane communication is normal.

8.3 Software Configuration

Use Gefran configuration software (to be obtained separately) for hardware configuration: scan the backplane to identify all modules and allocate I/O addresses.

Set gateway parameters: node ID, baud rate, protocol type, data mapping.

If communicating with a third-party PLC, a master station needs to be configured on the PLC side (such as importing GSD files into the Profibus master station).

Download the configuration to the gateway and test the I/O data exchange.

8.4 Common Problems and Solutions

Possible causes and solutions for the phenomenon

The gateway cannot go online due to the ERR LED being constantly on and insufficient power supply; Backboard damage; Gateway configuration error measuring 24 Vdc input, check current; Replace the backplane slot; Download configuration again

Part of the I/O modules were not recognized and the modules were not fully inserted; Poor contact of the backplane slot; Reinstall the module due to module malfunction; Clean the back panel contacts; Replace module testing

Inaccurate analog readings and poor grounding; Common mode interference; Range setting error check shielding grounding; Add signal isolators; Calibration range in software

GDNET communication timeout network cable fault; Switch configuration error; IP address conflict testing using cross network cable direct connection; Check the R-SW5 configuration; Ensure that the IP is in the same network segment

After replacing the module, rewiring is required. If there is no GILOGIK II wiring terminal, it can be retained on the original module. When replacing the module, unplug the terminal plug and insert the new module without rewiring

Practical Maintenance and Troubleshooting

9.1 Daily Maintenance

Regularly check whether the buckle between the backboard and the module is secure, especially for equipment that is subject to vibration.

Clean the air filter (if installed with ventilation openings) to ensure that the temperature inside the cabinet does not exceed 50 ℃.

Check if the spring terminal wiring is loose (gently press the wire with a screwdriver and it should not come off).

Monitor gateway logs (read fault history through configuration software).

9.2 Troubleshooting Process

Observe LED: All modules have power (PWR) and fault (ERR) indicator lights. Power LED off → Check the backplane power supply and fuse.

Use isolation method: unplug all I/O modules, leaving only the gateway. If the gateway communication is normal, plug back the modules one by one and locate the faulty modules.

Check on-site wiring: For digital input without signal, use a multimeter to measure the voltage between the input terminal and the common terminal. Measure the voltage at the output terminal and check the load for no action on the output.

Software diagnosis: Read the I/O module status and bus error counter through the diagnostic interface of the gateway.

Replacement testing: Prepare backup modules and quickly replace suspicious modules for verification.

9.3 Suggestions for spare parts

It is recommended to reserve at least the following spare parts:

1-2 pieces of each commonly used I/O module

An 8-slot backplate (R-BUS8)

Gateway module (based on the main protocol used on site)

R-CON series terminal blocks (20 pin, 36 pin, etc.)

Shielding and grounding accessories