• Manufacturer : MTL Instruments
• Product No : MTL4851
• Product type : HART® Multiplexer
• Number of channels : 32
• Channel transmitter type : HART rev 5 – 7
• Channel interface : 2 connections to each channel field loop (64 total)
• Host system interface : RS485 2-wire multidrop (up to 63 MTL4850 modules can be connected to one host)
• RS485 baud rate : 38400, 19200, 9600, 1200 baud – (auto-detected)
• Address selection : 8-bit interface, up to 64 addresses
• Channel-to-channel isolation : 50V dc
• Field loop isolation : 50V dc Module is coupled to loops via capacitor in each connection leg (i.e. 2 capacitors per channel)
• Supply voltage : 19V to 35V dc
• Currrent consumption : 60mA at 24V ±10%
• Power dissipation : <1.6W at 24V ±10%
• PSU protection : Reversed polarity protected Fused (375mA)
• Temperature range Operating: –40°C to +70°C Non-operating: –40°C to +85°C
• Relative humidity : 5% to 95% – non-condensing
• Dimensions (LxWxH) : 1.8cm x 12.4cm x 10.62cm
• Weight : 0.125 Kg
• Shipping weight: 1 kg

A repeater, in network transmission, serves the purpose of extending the network transmission distance. This paper will focus on the type of repeater, connection mode, application scenario of three directions, and further elaborate the important role of repeater in network transmission.

Four common types of Repeaters

(1) Twisted pair repeater. Both interfaces are twisted pair interfaces, which are used to extend the transmission distance of twisted pair cables.

(2) Optical cable repeater. Both interfaces are optical cable interfaces, which are used to extend the transmission distance of optical cables.

(3) Cable TV signal amplifier. It is a repeater used extensively in cable television networks.

(4) Fiber repeater. For twisted pair and optical cable signal conversion, the general outdoor transmission medium uses optical cable transmission, two sections of equipment only twisted pair interface and no optical cable interface, we can use the optical fiber repeater for signal conversion.

There are many kinds of Repeaters in different communication technologies, such as ADSL Repeaters, SDH regenerative Repeaters, PON optical Repeaters, etc., which are Repeaters for different network technologies.

Second, the connection mode of the repeater

Under normal circumstances, the two ends of the repeater are connected to the same media, but some Repeaters can also complete the transfer of different media. Theoretically, the use of Repeaters is unlimited, and the network can therefore be extended indefinitely.

In fact, this is not possible, because the delay range of the signal is specified in the network standard, and the repeater can only work effectively within the prescribed range, otherwise it will cause network failure.

For example, Ethernet often uses Repeaters to extend the cable length of the bus, and the length of each section of the standard thin cable Ethernet is up to 185 meters, and there can be up to 5 sections. For example, the maximum length of the Ethernet standard order section signal transmission cable is 500 meters, but after the use of Repeaters to connect 4 sections of cable, the Ethernet signal transmission cable can be up to 2000 meters, and the Ethernet repeater can use up to 4, that is, up to 5 Ethernet network segments can be interconnected, and the interconnected network segment belongs to a large Ethernet. It just extends the coverage of Ethernet. Some brands of Repeaters can connect cables of different physical media, such as twisted pair and optical cable, and the longest expansion distance is also different from different transmission media.

In particular, it is important to note that the repeater only sends data on any cable segment to another cable segment, regardless of whether the data contains incorrect data or data that is not suitable for the network segment.