1. Ethernet connectivity
   This module is most likely designed to facilitate Ethernet communications. Modules in this family typically support Fast Ethernet or Gigabit Ethernet speeds. For example, some of the modules in question can operate at 10/100/1000 Mbps, enabling high-speed data transfer between network devices. Such speed ranges make them suitable for a variety of industrial and enterprise applications where fast data exchange is critical, such as factory automation systems, data centres or large office networks.
   It may have multiple Ethernet ports. Other GMM – series modules have different port configurations, such as 8-port or 16-port setups. These ports may be a mix of copper (RJ45) and fibre optic (e.g. small pluggable SFP, multimode SC or single mode SC) interfaces. Copper ports are cost-effective for short-distance connections within a building or small area, while fibre optic ports are ideal for long-distance, high-bandwidth and interference-free transmission.
2. Compatibility
   Compatible with industrial Ethernet switches such as Hirschmann’s Greyhound 1020/1030 series. Compatibility with these switches ensures seamless integration into existing or new network infrastructures. The modular design of these switches allows for easy expansion by adding media modules such as GMM20 – MMMMMMEV9HHS9XX, enabling users to customise their network setup to their specific requirements. For example, if an existing network needs to add more fibre optic connections for a new remote sensor network, the module can be added to a suitable Hirschmann switch.
   The module also offers a degree of compatibility with other industry-standard Ethernet devices, depending on the specific protocols and electrical/physical interface standards supported by the module.
3. Industrial Grade Reliability
   Hirschmann is known for manufacturing industrial-grade networking equipment, and the GMM20 – MMMMMMEV9HHS9XX is no exception. It is designed to withstand harsh environmental conditions. This may include a wide operating temperature range, similar to other industrial modules that can operate in temperatures ranging from – 40°C to + 70°C. The GMM20 – MMMMEV9HHS9XX is designed to withstand harsh environmental conditions. This makes it suitable for use in outdoor applications, industrial plants at extreme temperatures or in areas with poor climate control.
   It can also provide protection against electrical interference, for example by complying with electromagnetic compatibility (EMC) standards. This ensures that the module operates reliably in electrically noisy environments, for example in plants with large motors, distribution systems or other electrical equipment.
4. Management and configuration
   The modules can support basic network management functions. Some similar Hirschmann modules can be configured through a web-based interface, command line interface (CLI), or Simple Network Management Protocol (SNMP). This allows network administrators to set parameters such as port speeds, VLAN (virtual LAN) assignments, and security settings. For example, VLANs can be used to segment the network for security or traffic management purposes, and the ability to configure these parameters on the module adds flexibility to the overall network design.
   The modules also support features such as link aggregation, which allows multiple physical ports to be grouped together to provide higher bandwidth and redundancy. This is useful in applications that require high availability and increased throughput, such as server-to-switch connections in data centres.
5. General safety provisions
   This equipment is powered on and in operation. Improper use may result in personal injury or property damage. Proper transport, compliant storage, installation, and careful operation and maintenance are prerequisites for safe and trouble-free operation of the equipment.
   Read this document, safety tips and warnings before connecting any cables.
   Use only undamaged parts.
   Repair parts are not included with the device. In case of malfunction or damage, disconnect the power supply and send the device to Hirschmann for inspection.

Intended use
The product is to be used only for the applications described in the Hirschmann product information and in this manual.
Use this product only within the limits specified in the technical data. See ‘Technical Data’ on page 57.
Connect this product only to components that meet the requirements of the respective application.

Installation position requirements
When installing, please observe the regulations of the country in which the equipment is to be operated.
When the ambient temperature is below -10°C, wiring suitable for the lowest temperature must be used.
For equipment models with supply voltage N (110VDC): See ‘Equipment Names and Product Codes’ on page 21. This equipment must be installed only in an operating mechanism with restricted access and accessible only to maintenance personnel. Install the device correctly to avoid mechanical shocks from the power supply area.
Hint: Risk of torsion, contact problems and gradual breakage if stress relief is not sufficient.
Reduce the effects of mechanical stress on cable and wire connection points.
Strain relief devices should be designed to prevent any mechanical damage to cables, wires or conductors from external influences or their own weight.
To prevent damage to the device connections, plug-in connectors and cables, observe the correct installation instructions in DIN VDE 0100 520:2013 – 06, sections 522.6, 522.7 and 522.13.

Enclosure
The housing may only be opened by specialists authorised by the manufacturer.
Never insert sharp objects (narrow screwdrivers, wires or similar) into the interior of the device or into the wire connection terminals. Do not touch the connection terminals.
Mount the device vertically with the antenna facing upwards.
When the ambient temperature is > + 60°C: The surface of the device chassis may be very hot. Do not touch the device during operation.

Personnel qualification requirements
Only qualified personnel should be assigned to operate the equipment. Qualified personnel should have the following characteristics:
Qualified personnel have received appropriate training. Training and practical knowledge and experience constitute personnel qualifications. This is a prerequisite for the connection, earthing and labelling of circuits, equipment or systems in accordance with current technical safety standards.
The competent person is aware of the hazards of the work.
The competent person knows the appropriate measures to deal with these hazards in order to reduce the risk to himself and others.
The competent person receives regular refresher training.
National and international safety regulations
Note whether the electrical installation complies with local or national safety regulations.
Grounding
Ground the unit through the earth wire connector on the unit itself.
Ground the unit before connecting other cables.
Disconnect all cables from ground at the end. The entire shield of the connected shielded twisted pair cable is electrically connected to the grounding wire connector on the metal housing.
Prerequisites for connecting wires
Before each connection of wires, make sure that the stated prerequisites are fulfilled.

Installation
The unit is shipped from the factory in a standby condition. To avoid contamination of the exposed contacts when the components are set aside and not installed, store all components of the system together in a dry, clean workplace. The device complies with the IP65/67 protection class only if
All connected connectors and cables are IP65/67 rated.
All unused connections and ports are sealed with the appropriate protective screws.
The protection screws supplied as accessories are IP65/67 rated.

Connecting the data cable
Follow the general recommendations below for wiring data cables in high interference environments:
Choose the shortest possible data cable.
Use fibre-optic cables for data transmission between buildings.
When wiring with copper cables, make sure that there is enough space between the power and data cables. It is best to install the cables in separate cable trenches.
Please note that power and data cables should not run in parallel over long distances. To minimise inductive coupling, ensure that the power and data cables are crossed at an angle of 90°.
For Gigabit transmission, use shielded data cables with more than copper wires, e.g. SF/UTP cables according to ISO/IEC 11801. For all transmission rates, use shielded data cables according to EN50121 – 4 and the requirements for marine applications.