Installation 3-13
SIMATIC TIWAY I Series 500 NIM User Manual
Local/Remote. When set to remote, this two-position switch enables the
NIM to perform write operations to controller memory. In the local position,
the NIM cannot write to the controller. In either position, the NIM can
monitor P/C memory and mode of operation. The Local Mode will be
indicated (after the NIM is brought into the online state) by a flashing
Online LED indicator. The Remote Mode will be indicated by a continuously
illuminated online indicator.
Local Line Bias. For earlier NIMs supplied with Local Line media
interfaces, a toggle switch is provided which allows selection of bias or no
bias for the Local Line. This switch places a 100 millivolt potential between
each of the two active conductors in the cable. The Local Line must be
biased to prevent undesired oscillations at the receivers connected to the
line. Bias should be applied only by two units (one at each end of the cable)
in the network.