3. Installation. Weidmuller SL-MOD-GW

Weidmuller SL-MOD-GW is an industrial-grade Modbus/TCP gateway designed to seamlessly integrate Modbus RTU/ASCII devices into an Ethernet network. It enables transparent data exchange between Modbus serial devices and Modbus TCP clients, making it easy to monitor and control your devices from a remote location or SCADA system. The SL-MOD-GW supports up to 5 simultaneous Modbus TCP client connections.

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3. Installation

3.1 Regulatory notes

1. The SL-MOD-GW is suitable for use in non-hazardous locations only.

2. The SL-MOD-GW is not authorized for use in life support devices or systems.

3. Wiring and installation must be in accordance with applicable electrical codes in accordance with the authority having jurisdiction.

4. This is a Class A device and intended for commercial or industrial use. This equipment may cause radio interference if used in a residential area; in this case it is the operator’s responsibility to take appropriate measures.

5. The precondition for compliance with EMC limit values is strict adherence to the guidelines specified in this set of instructions. This applies in particular to the area of grounding and shielding of cables.

FCC Notice (USA only)

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part

15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.

Industry Canada Notice (Canada only)

This Class A digital apparatus complies with Canadian ICES-003.

3.2 Unpacking, handling and storage

1. Please read this set of instructions. carefully before fitting it into your system.

2. Keep all original packaging material for future storage or warranty shipments of the unit.

3. Do not exceed the specified temperatures.

3.3 Before connecting anything

1. Before installing or removing the unit or any connector, ensure that the system power and external supplies have been turned off.

2. Check the system supply voltage with a multimeter for correct voltage range and polarity.

3. Connect the power supply cable and switch on the system power. Check if the Power LED is lit.

4. Turn off system power.

5. Connect all I/O cables.

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6. Once you are certain that all connections have been made properly, restore the power.

3.4 DIN rail mounting and removal

The SL-MOD-GW gateway is designed to be mounted on a 35 mm DIN rail according to DIN/EN 50022. The enclosure features a 35 mm profile at the back which snaps into the DIN rail. No tools are required for mounting.

Please observe the rules outlined in Section 3.5, “Mounting rules”.

To mount the unit on a DIN rail, slot the top part of the

SL-MOD-GW into the upper guide of the rail and lower the enclosure until the bottom of the red hook clicks into place.

DIN rail

Click 2

To remove the SL-MOD-GW from the DIN rail, use a screw driver as a lever by inserting it in the small slot of the red hook and push the red hook downwards. Then remove the unit from the rail by raising the bottom front edge of the enclosure.

Slide down 2

3.5 Mounting rules

The enclosure provides protection against solid objects according to IP 20 / NEMA Type 1 protection rating.

When mounting the unit observe the following rules:

• No water splash and water drops

• No aggressive gas, steam or liquids

• Avoid dusty environments.

• Avoid shock or vibration

• Do not exceed the specified operational temperatures and humidity range.

• Mount inside an electrical switchboard or control cabinet.

• Make sure there is sufficient air ventilation and clearance to other devices mounted next to the unit.

• Observe applicable local regulations like EN60204 / VDE0113.

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3.6 Powering the SL-MOD-GW

Before connecting power please follow the rules in the section called “Safety Precautions” and

Section 3.3, “Before connecting anything”.

Power is supplied via a 3.81 mm 2-pin pluggable terminal block located at the top side of the mounted unit

(refer to Figure 2.1, “Location of connectors”). The following table and picture shows the power terminal socket

pinout:

Pin

Signal Function

V+

V-

Positive voltage supply (10 - 30 V DC)

Negative voltage supply, DC power return

Table 3.1: Power supply connector pinout

Caution

Make sure that the polarity of the supply voltage is correct before connecting any device to the serial ports! A wrong polarity can cause high currents on the ground plane between the

V- power supply pin and the serial port ground pins, which can cause damage to the device.

3.7 Wiring the RS-485/422 interface

The RS-485/422 port is used for integrating the SL-MOD-GW into a two-wire or four-wire Modbus over Serial

Line network. The use of either the RS-485 or RS-422 interface must be configured using the web interface

(See Section 5.3.2, “Configuring serial line Modbus”). The SL-MOD-GW is a Modbus Master device on this

interface.

The RS-485 and RS-422 signals are located at the 3.81 mm 6-pin pluggable terminal block on the top side of the

mounted unit (refer to Figure 2.1, “Location of connectors”). The following table and picture shows the pinout:

RS-485

RS-422

Pin

RS-485 signal

GND

D+

D-

Table 3.2: RS-485/RS-422 connector pinout

RS-422 signal

GND

TX+

TX-

GND

RX+

RX-

Description

Modbus Common

Modbus D1 or TXD1

Modbus D0 or TXD0

Modbus Common

Modbus RXD0

Modbus RXD1

• Line termination is required and is typically done with a 120 Ohm 1/4 W resistor. For RS-485 operation the bus must be terminated at both ends. For RS-422 operation a termination resistor must be inserted between the RX+/RX- signals.

• Maximum number of RS-485 nodes without repeater is 32.

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• Stub connections off the main line should be avoided if possible or at least be kept as short as possible. Stub connections must not have terminating resistors.

• Maximum cable length to 1200 m (4000 ft).

• To assure a high degree of electromagnetic compatibility and surge protection the cable should be twisted pairs and shielded. An additional cable conductor or pair may be used for the GND reference.

Caution

Do not connect the cable shield to the GND pins! Use an external chassis ground connection to terminate the shield.

3.8 Wiring the RS-232 interface

The RS-232 port can alternativly be used for serial communication to a Modbus Slave device instead of RS-485.

The use of the RS-232 interface must be configured using the web interface (See Section 5.3.2, “Configuring serial line Modbus”). The SL-MOD-GW is a Modbus Master device on this interface.

The Modbus RS-232 connector is a male 9-pin D-sub type located at the bottom side of the mounted unit (refer

to Figure 2.1, “Location of connectors”). It has industry standard EIA-574 data terminal equipment (DTE) pinout

as shown in the following table and picture:

Pin

Table 3.3: Modbus RS-232 connector pinout

Signal Function

DCD (unused)

RXD Receive data

TXD

DTR

GND

DSR

Transmit data

(unused)

Signal ground

(unused)

RTS

CTS

(unused)

Direction in in out out in out in in

• Maximum cable length is 15 m (50 ft) or a length equal to a line capacitance of 2500 pF, both at the maximum standard bit rate of 20 kbps. If operating at higher bit rates the maximum cable length drops to 3 m (10 ft) at a bit rate of 57.6 kbps.

• To assure a high degree of electromagnetic compatibility and surge protection the RS-232 cable should shielded. The shield shall be connected to an external chassis ground at the either or both ends, depending on the application.

• The shield must not be connected to the GND pin.

Note

To connect the SL-MOD-GW to a PC (Personal Computer) or any other device with data terminal equipment (DTE) pinout you need a null-modem or cross-over cable.

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