GFK-2892F
March 2019
37
Chapter 4
System Operation
This chapter provides a System Overview and describes:
•
Communications
•
Redundancy
•
I/O Scans
•
Alarms
4.1
System Overview
Communications
As shown in Figure 7, the Genius Gateway (GCG001) sits on a PROFINET network which is connected to a
PROFINET Controller (PNC001, for instance). The PROFINET Controller is mounted in an RX3i rack. This aspect
of the architecture allows the RX3i to interact with the GCG001.
The PROFINET network to which the GCG001 is connected operates at 100Mbps only. The Network Speed will
be set through auto-negotiation if necessary. Details of PROFINET communications may be found in the
PACSystems RX3i & RSTi-EP PROFINET I/O Controller Manual
GFK-2571.
The GCG001 is also connected to a Genius Bus. It takes the place of a traditional Genius Bus Controller,
meaning it is capable of communicating with up to 31 other Genius Devices.
The Genius Bus operates as a Local Area Network (LAN) using twisted pair wiring. The wiring is daisy-chained
via the terminal strips on each device, as shown in Figure 10. The Genius LAN will not be disrupted if power is
lost on one its networked devices, since the wiring passes through each device without requiring any active
electronics to be present. The LAN cabling must be terminated at both ends of the cable run, using resistors,
the value of which matches the impedance of the cable used in the application. See Figure 11 for terminating
the bus at the GCG001.
The Genius Bus is capable of operating at a number of different baud rates. All devices on the bus must operate
at the same agreed baud rate. For further details, refer to the
Genius I/O System and Communications User's
Manual,
GEK-90486-1
.
The default baud rate of the GCG001, when shipped from the factory is 153.6 kBaud.
This may be changed via the PME configuration software.
In the event the baud rate needs to be changed, the following sequence is recommended:
1.
Disconnect the GCG001 module from the Genius bus.
2.
Change the baud rate to the new value on all Genius devices connected to that bus.
3.
Cycle power to all Genius devices on which the baud rate has just been changed.
4.
Use the HHM to verify the baud rate was successfully changed on each device.
5.
Retry the above steps on any devices that failed to switch over to the new baud rate.
6.
Using PME, configure the GCG001 module to operate at the new baud rate.
7.
Reconnect the GCG001 to the Genius bus.
8.
Note that the HHM will not work reliably on a mixed baud rate bus. Connect the HHM directly to
any device under these circumstances and disconnect that device from the Genius bus
temporarily. The baud rate of the HHM can be altered (via the HHM keyboard) to match the
configured baud rate of the device (which may be unknown). Once both the HHM and target
device are set to the same baud rate, the HHM can command the target device to change to a
new baud rate, which will take effect upon power cycling the device. Remember to then change
the baud rate of the HHM to the new baud rate.
