cable. The outer shield around the cable consists of a braided mesh. In addition, every twistedpair has a foil shielding.If you use an S7FTP patch cable for ethernet, be aware that a cross-connected cable has onlypairs on pin 1-2 and 3-6 cross-connected. The two remaining pairs are not cross-connected.Clock configuration switchAs of transceiver 21-216 revision 2, a rotary switch is added to the front panel to easeinstallation and testing (see Figure 72).When two transceivers 21-216 are used in a PDH system, they are set as slaves when anexternal clock is used.Clock synchronization configurationThe rotary switch on the front panel has 16 positions (HEX switch). At position 0 the switch’sarrow, visible through the adjusting hole, points straight down (see Figure 72). In this position,external clock is selected (default).IEC07000249-1-en.vsdxIEC07000249 V1 EN-USFigure 72: Rotary switch for clock synchronization configurationPosition Function0 External clock is selected (slave)1 External clock is selected and inverted (slave)2 Internal clock is selected (master)3 Internal clock is selected and inverted (master)4–7 Reserved for future use8–15 Reserved for factory testingBack-to-back testingWhen performing back-to-back testing with G.703 ports directly connected, one transceiver21-216 is set as a master (internal clock).5.5.4 Power-up and LED statuses with transceiver 21–216GUID-13DA5C8C-39C3-4643-87BF-31B9428DF496 v1To power up transceiver 21–216, connect the power cord to the transceiver, and then connectthe other end of the cord to mains. If the link does not work, try to cross-connect the fibre atone end.1MRK 505 382-UEN E Section 5Communication set-upCommunication set-up, 670/650 series 73Application Guide© Copyright 2017 ABB. All rights reserved
