The Quantum processor rack is always DROP 1, regardless if it is used for hot standby or not.
For a hot standby configuration, two (2) IDENTICALLY configured PLC CPU racks are connected with the Hot Standby kit (fibre optic connection). The same module types must be in the same positions in each PLC CPU rack. Address swapping is handled automatically by the software.
When used in a hot standby configuration, this drop (the PLC CPU drop, drop #1) cannot have any I/O modules in it (discrete, analog or counting).
However, it can contain communication modules (Modbus Plus, Ethernet).
For a hot standby system, all I/O is remote. The I/O modules are located in drop 2 to whatever is required. They are connected using the Remote IO network to both processors.
Basically, both processors "read" the IO but only one "talks" to the IO. The processors "talk" to each other to keep in step and to ensure that both have current values. During a fail over, the IO module states are "held" until the transfer is completed.
> Does Quantum Hotstandby should have one number RIO drop? If possible illustrate with an example...
A Quantum Hot Standby can communicate to I/O that is local to the primary and secondary racks, Remote I/O, Distributed I/O or Ethernet. A Quantum Hot Standby Planning Guide can be found at www.modicon.com
> Does Quantum Hotstandby should have one number RIO drop? If possible illustrate with an example...
I have installed and configured a Quantum Hot Standby system, and you can address the primary PLC as whatever MB address you prefer, although it is customarily set to something under 10. The secondary PLC is setup as the original plus 32. So, if the primary is set to MB address 2, then the secondary would be 34. You would typically connect the primary and secondary with Modbus Plus cable so that the secondary can assume the MB address of the primary in case of a crash. You would also typically have a fiber optic cable connecting the two controllers so that you can transfer the PLC ladder program and I/O states over the fiber cable.
If you email me at [email protected], then I can give you more information about this as it applies to your application.
The TSX Quantum Hot-Standby System uses the 140CRP93x00 (RIO Head) in each of the CPU Racks and the 140CRA93x00 (RIO Drop)for the I/O racks. The 140CRP93x00's are assigned a Drop address of 1. For the 140CRA93x00's the only addresses that are valid are 02 - 32.
The TSX Quantum Hot-Standby ONLY allows a single 140CRP93x00 (RIO Head) to be installed in each CPU rack.
Regards
Robert Willis
Square D Company
Houston, Texas
E-Mail: [email protected]
