Rockwell Automation AutoMax ControlNet Communication Interface Module - Manual (Page 57)

AutoMax ControlNet Module Page 57
Publication number DSMBCN-UM001B-EN-P February 2003
Viewing Network Parameters
The network parameters include the network update time (NUT), the
maximum scheduled address (SMAX), the maximum unscheduled
address (UMAX), and the network redundancy (channel A only, Channel
B only, or both).
There are additional network parameters that depend on the devices on
the network, the network media type and length, and so on.
The MBCN has tables that contain the values assigned. Refer to the
ControlNet specification for detailed information on what these registers
contain.
In normal operation, it will not be necessary to use these registers.
Current Network Parameters
An application can use the following registers to view the current
network parameters. These registers should be regarded as read-only.
NOTE: The active network keeper periodically sends a packet called the
TUI that indicates the status of the network keeper to the other nodes on
the network.
Name Register Description
CurNutLen 9304 Network update time (NUT) in 10 µs
increments
CurSMax 9305 Maximum scheduled address. This is
the highest address allowed to
transmit scheduled data.
CurUMax 9306 Maximum unscheduled address. This
is the highest address allowed to
transmit unscheduled data.
CurSlotTime 9307 Slot Time. This is the maximum time
to wait for a node to transmit (in 1
µs
ticks)
CurBlanking 9308 Minimum gap between frames (in 1.6
µs ticks) (always 6)
CurGbStart 9309 Guard Band Start Time (in 10 µs ticks)
CurGbCenter 9310 Guard Band Center Time (in 10 µs
ticks). This is when the moderator
node sends the moderator packet.
CurModulus 9312 Modulus (always 127). This is different
from the scheduling modulus.
CurGbPrestart 9313 Guard Band PreStart Time (in 10 µs
ticks)