General
Data bits	7, 8
Stop bits	1, 2
Modules per side	je 24
Operating temperature	-40–75 °C
Storage temperature	-40–85 °C
MTBF	1.315.666 Stunden („-I“-Modell)

The MGate 4101I-MB-PBS-T from Moxa is an industrial protocol converter that connects Modbus devices with PROFIBUS-PLC systems such as Siemens S7-300/400. It serves as a gateway between serial Modbus end devices and PROFIBUS-DP networks, enabling the integration of heterogeneous fieldbus systems into existing automation installations. The devices are designed for use in demanding industrial environments and feature a robust metal housing construction as well as DIN rail mounting, allowing flexible installation in enclosures. The model designation “-I” indicates integrated galvanic isolation, which protects against overvoltages during operation, while the “-T” suffix denotes an extended temperature range of -40 to 75 °C.

Applications
This gateway is designed for industrial automation systems where Modbus end devices such as sensors, actuators, or small controllers are to be integrated into a higher-level control system via PROFIBUS-DP. Typical use cases include machine controls, manufacturing plants, or process control systems where devices from different manufacturers must communicate. Support for PROFIBUS DP-V0 Slave enables integration into existing PROFIBUS networks, which are commonly used in the manufacturing industry.

Functions and Equipment in Detail
The device features a serial interface with a DB9 male connector supporting RS-232/422/485. The baud rate can be set between 50 bps and 921.6 kbps, with configurable data bits (7 or 8), parity (none, even, odd, Space, Mark), and stop bits (1 or 2). Flow control is via RTS/CTS or DTR/DSR. The RS-485 interface includes automatic data direction control and an integrated 120 Ω terminator. The QuickLink function enables automatic configuration, I/O mapping, and monitoring, allowing commissioning within minutes. The PROFIBUS interface is implemented via a DB9 female connector and supports the PROFIBUS DP-V0 Slave protocol with baud rates from 9.6 kbps to 12 Mbps. Addressing is done via a rotary switch for addresses 0–99 or via software for addresses 100–125. The maximum data volume is 7744 bytes input and output. The gateway supports one master connection and can manage up to 32 sides with 24 modules each.

Technology Explained Simply
Protocol translation occurs between Modbus RTU/ASCII (Master and Slave) and PROFIBUS DP-V0. Supported Modbus functions include 1, 2, 3, 4, 5, 6, 15, 16, and 23, with up to 100 Modbus commands per device being processed. Integrated galvanic isolation with 2 kV protection voltage safeguards internal circuits against transient overvoltages, especially during electrical disturbances in the network. Power supply is via DC voltage from 12 to 48 VDC, with current consumption at 12 VDC being 275 mA. The connection type is a screw terminal (Euroblock). A relay output with 1 A at 24 VDC is provided for status indication, such as signaling operational states or faults.

Compatibility and Accessories
The gateway is compatible with PROFIBUS-DP systems, particularly Siemens S7-300/400 PLC systems. The serial interface supports Modbus devices communicating via RS-232/422/485. Integrated galvanic isolation increases immunity to interference and enables use in electrically harsh environments. Certifications include EMC (EN 55032/35, FCC Part 15B Class A), EMS (IEC 61000-4-2, -3, -4, -5, -6, -8), and safety standards (IEC/UL 60950-1, IEC/UL 62368-1). The devices are approved for use in hazardous areas according to ATEX, IECEx, and Class I Division 2. The MTBF is 1,537,948 hours for the standard model and 1,315,666 hours for the “-I” model, measured according to Telcordia SR332. The warranty is 5 years.

Mounting and Installation
Mounting is done via DIN rail, which is included in the delivery. The metal housing is IP30-protected, providing protection against solid foreign objects and limited splashing water. Dimensions are 36 × 105 × 140 mm, weight 500 g. Installation requires connecting serial Modbus devices via the DB9 interface and PROFIBUS-PLC systems via the DB9 female interface. Configuration is done via the integrated console port (RS-232, 8-pin RJ45, 115200 bps) using an RJ45-to-DB9 cable, which is also included in the delivery. The quick start guide supports commissioning.

Operational Advantages
The QuickLink function significantly reduces commissioning time, as configuration and mapping are done automatically. Galvanic isolation increases operational safety and prevents damage from overvoltages. The high MTBF and 5-year warranty highlight the device’s reliability. Support for Modbus functions 1 to 23 enables broad compatibility with various Modbus devices. The operating temperature range of -40 to 75 °C makes the device suitable for use in extreme environments, such as in process industries or outdoor applications.

Delivery Contents
The device is delivered with an RJ45-to-DB9 console cable, a DIN rail mounting kit, a quick start guide, and a warranty card. The gateway itself is included in the delivery.