English
TP cables (twisted pair) are either straight-through (UTP patch cable) or crossover cables.
The straight-through TP cable is the most common cable intended primarily for connections between the switch and the terminal device (network interface control unit on PC, PLC TC700, etc.), and it can also be used for direct connection of the Foxtrot systems. It is commonly produced and generally available. The cable is fitted with the RJ-45 (8 pins) connectors on both ends. Only four signals are functional (in the commonly used 10 Base-T interface), while the other wires are not used (in Fig. 1 they are indicated by a dashed line). Only the twisted pair cable must be used (untwisted phone cable cannot be used!), and one twisted pair must always be used for one direction of flow (e.g. RD). The colour-code of wires applicable for the Ethernet cables and most widely used is based on the TIA568B set of telecommunication standards; see Table 1.3.1.1 (valid for straight-through cables).
The data UTP (unshielded) and STP cables (shielded - shielding is not connected on the side of the PLC) are produced in several grades, numbered from 3 to 6. Any grade can be used for the 10/100 Mbit Ethernet (10Base-T), but the minimum recommended grade is 5.
A basic assortment of straight-through cables is supplied under the order number TXN 102 05.xx (the last digits represent the cable length in accordance with the product range - see the TC700 catalogue). The maximum length of the TP cable is limited to 100 m.
Fig. 1 Wiring a straight-through cable (the ETHERNET UTP patch cable)
The crossover cable is used for a direct connection of two equivalent devices (e.g. HUB - HUB, without using an uplink port on the hubs). It is not so easily available and it must be ordered with an explicit specification for a crossover cable. The cable is fitted with the RJ-45 (8 pins) connectors on both ends. Only four signals are functional (in the commonly used 10 Base-T interface), while the other wires are not used (in Fig. 2 they are indicated by a dashed line). Only the twisted pair cable must be used (untwisted phone cables cannot be used!), and one twisted pair must always be used for one direction of data flow (e.g. RD).
A basic assortment of cross cables is supplied under the order number TXN 102 06.xx (the last digits represent the cable length in accordance with the product range - see the TC700 catalogue).
Fig. 2 The wiring of the crossover TP cable in the ETHERNET