14
1
VMIACC-5595 Installation Guide
Both the serial port interface and the Ethernet interface can be used at the same time.
Multiple Ethernet users are also possible. At times this feature is actually useful. It can
be tedious to temporarily change your PC’s Ethernet port to a range that matches the
default factory settings, if restoring the defaults becomes necessary. On some
machines, it could require a time consuming multi-reboot process. By using the serial
port only to re-establish the IP settings, the process becomes easier.
The total signal propagation delay through the entire VMIACC-5595 hub is
25 nanoseconds — equivalent to the delay through approximately 18 feet of cable.
The switching time depends on the Detection Mode used: LOS, Single Sync mode or
Multi-Sync mode.
For the Single Sync Detect Mode, the auto bypass switch delay will be approximately
0 to 15.5µsec. For the Multi-Sync mode, the auto bypass switch delay is approximately
4 times 15.5µsec or 62µsec provided four consecutive invalid sync periods occur. The
auto bypass OFF switching delay for the LOS Detect Mode is approximately 100µsec.
The auto bypass ON switching delay for the LOS Detect Mode is approximately
1.25msec. Also note that upon power-up of the hub, all ports will default to bypass
ON.
NOTE:
The switching time values are difficult to measure accurately, so they are
estimated and based on component specifications.
The power up delay of the VMIACC-5595 is less than 2 seconds. This is measured
from the time power is first applied to the time the Ethernet Link light is truly
asserted. The last event to complete at power up is the boot of the Ethernet module’s
imbedded processor. The optical ports are operational in the default mode (auto
bypass based on LOS) in approximately 1 second after power is applied. The bypass
circuitry of this hub is not passive. Power must be applied to the unit before it will
pass network data.
All the control settings, not just the communication settings, are stored in non-volatile
memory. If power is lost or interrupted, the hub will return to the last good
configuration, once the processor boot cycle is complete.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com