Grass Valley CRSC v.3.2 - Manual (Page 22)

10
Introduction
CRSC Summary
Subnet Masks
A subnet mask a set of bits that Ethernet uses to divide an IP address into a subnet field and a
field for a device address that exists in that subnet. For compact routers, the typical subnet mask
is 24 bits (out of 32):
11111111 11111111 11111111 00000000
and this is typically represented by 255.255.255.0. For such a subnet, there are 256 possible
device addresses. The addresses 0 and 255 are reserved. Device addresses can therefore range
from 1 to 254.
The subnet masks need not be 24 bits. If it differs, the device address range will be something
other than 1–254.
Rotary Switches
The 16-position ‘Frame ID’ rotary switches (located at the front of a router or remote panel
module) are used in the following circumstances:
• When a router is stand-alone or in a stand-alone network.
• In a CRSC network, when the router or remote panel module is still in its default state (e.g.,
when you are in the process of adding a router or remote panel module to the CRSC net-
work).
Otherwise, in a CRSC network, the rotary switch settings have no importance.
Adding Devices to a CRSC Network
When you are adding a router or remote panel module to a CRSC network, the 16-position
rotary switch determines its initial IP address. Routers and remote panel modules usually come
from the factory with the rotary switch set to position 1.
The 16 positions are numbered (in hex) from 0 to F. In hex notation, letters represent digits
greater than 9:
A = 10, B = 11, C = 12, D = 13, E = 14, F = 15
The value of the switch is then added to a fixed number to create the initial IP address for the
router or remote panel module. Letting the subnet be represented by xxx.yyy.zzz,
For CQX routers, the IP address = xxx.yyy.zzz.sss where sss = switch value + 200. Use only a
switch setting in the range 1–4 (resulting in an address range of 201 to 204).
For other compact router routers, the IP address = xxx.yyy.zzz.sss where sss = switch value +
100 (resulting in an address range of 101 to 104).
For remote panel modules, IP address = xxx.yyy.zzz.sss where sss = switch value + 50. Use
only a switch setting in the range 1–15 (resulting in an address range of 51 to 65).
Note carefully that if a rotary switch is set to zero, the router or panel reverts to the factory
default state (when it powers up) and not to a previously set state. Do not use a switch setting of
0 when you are adding a router or remote panel module to a CRSC network!
A router and a remote panel module can have the same switch setting because each is being
added to a different base number. However, two routers or two control panels cannot have the
same switch setting because the resulting number would be the same, creating identical IP
addresses.