Microgate SyncLink GT2, Руководство пользователя по оборудованию

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Differential Input Termination
Each port on the card has optional termination of RS ‐ 422/485 differential inputs. When a resistor pack is
installed in the socket labeled ‘TERM’, all differential inputs for that port are terminated with 120 ohms.
By default the termination resistor pack is installed for all ports. The presence of the termination resistor
pack does not affect single ended (RS ‐ 232/V.28) inputs.
Termination is used to increase signal reliability at high speeds (generally 1Mbps or more). At high
speeds, receivers at each end of a cable should be terminated. For a multi ‐ drop setups (more than 2
devices on a cable), do not terminate receivers connected to the middle of the cable. At slower speeds,
the termination can usually remain without problem. Removing termination at slower speeds may allow
the use of longer cables.
To remove a termination resistor pack, identify the socket labeled ‘TERM’. Then remove the yellow
resistor pack from the black socket using a flat head screw driver or equivalent tool. Termination can be
reinstalled by pressing the resistor pack back into the socket. Take care that the pins on the resistor pack
are not bent and are firmly seated into the socket.
Figure 3 Termination Sockets