Quantum Hot Standby and 140 NOE 771 •1 / 140NOC78•00 Modules
Original instructions
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Description of the Hot Standby Solution
NOTE: The Quantum Hot Standby system supports up to six 140 NOE 771 •1 Ethernet communication modules, up to four 140NOC78000 Ethernet distributed I/O head modules, and one 140NOC78100 Ethernet control head module.
The NOE communications modules supported are:
The Hot Standby 140 NOE 771 •1 / 140NOC78•00 modules allow automatic IP address swap during a switchover. Both controllers are configured identically. One controller has the primary communication head module; the other controller has the standby module.
In a Quantum Hot Standby system, there is no switchover triggered if a NOC/NOE module becomes non-operational. Therefore, the user logic must force a switchover in this case, if needed.
NOTE:
  • For detailed information about the 140NOC78000 distributed I/O head module, refer to the Quantum EIO Distributed I/O Network Installation and Configuration Guide.
  • For detailed information about the 140NOC78100 control head module, refer to the Quantum EIO Control Network Installation and Configuration Guide.
CAUTION
LOSS OF CONTROL
Use an Ethernet switch (not a hub) or BMX NRP 020• fiber converter modules to connect 140 NOE 771 •1 / 140NOC78•00 Quantum Ethernet modules to each other and to the network.
Failure to follow these instructions can result in injury or equipment damage.
NOTE: Schneider Electric recommends that you connect the 140 NOE 771 •1 / 140NOC78•00 modules in the primary and standby racks to the same switch. Connecting 2 of these modules to the same switch minimizes the probability of a communication interruption.
A 140 NOE 771 •1 / 140NOC78•00 module waits for a change in the controller’s Hot Standby state. If the module detects that the new Hot Standby state is either primary CPU or standby CPU, then it changes the IP address.
Client/server services (I/O scanning, global data, messaging, FTP, SNMP, and HTTP) continue to run after the switch from the old to the new primary 140 NOE 771 •1 / 140NOC78•00 module.
NOTE: If a 140 NOE 771 •1 / 140NOC78•00 module stops communicating, the primary CPU does not go offline.
WARNING
UNINTENDED EQUIPMENT OPERATION
Design your application so that un-monitored modules support communication only to noncritical parts of the application.
Failure to follow these instructions can result in death, serious injury, or equipment damage.
Hot Standby and 140 NOE 771 •1 / 140NOC78•00 Module Functionality
The 140 NOE 771 •1 / 140NOC78•00 module provides different Ethernet services for the Quantum Hot Standby system.
The following table identifies the services that are available:
Service
Availability
I/O Scanning
Available
Global Data
Only available in the 140 NOE 771 •1 modules
Modbus Messaging
Available
FTP/TFTP
Available
SNMP
Available
HTTP Server
Available
DHCP Server
Only available if the module is in the primary rack
NTP
Available on NOC modules
NOTE:
  • The 140 NOE 771 •1 modules support a Quantum Hot Standby system starting with Unity Pro V2.0.
    Unity Pro is the former name of Control Expert for version 13.1 or earlier.
  • The 140NOC78•00 modules support a Quantum Hot Standby system starting with Unity Pro V7.0.
Impact of Using Global Data in a Quantum Hot Standby System
140NOE771•1 firmware version 6.5 or later
WARNING
UNINTENDED EQUIPMENT OPERATION
Do not use global data in systems that require periodic command swapping.
  • Swap is the time the system takes to switch from Primary to Standby with all configured services started.
  • IP-Swap is the time the system takes for the Primary (old Standby) to issue a gratuitous address resolution protocol (ARP), which helps detect IP conflict, showing the Primary is using IP, not IP+1.
Hot Standby with Global Data
It is recommended that if periodic swapping is used in a Hot Standby system, use IO scanner instead of Global Data.
  • IP-Swap can take up to 6 seconds when Global Data is configured.
    • During this time the new Primary continues to use IP+1 which may cause a BUMP in the system.
  • If Global Data and IO Scanner are used in a Hot Standby system, it can take up to:
    • 4 * (watchdog) + 6 seconds
  • If you use Global Data in a Hot Standby system, configure device hold up time as:
    • 7 seconds for IO Scanner to start
    • 1 minute for Global Data to start
Failure to follow these instructions can result in death, serious injury, or equipment damage.