IBM SG24-5360-00 manual Determining the Logical Control Unit Number for RVA

5.6.1 Determining the Logical Control Unit Number for RVA

You can calculate the LCU number by using the CUADD value used in the IOCP configuration for each LCU. Each of the four CUADDs contains 64 devices.

If the device numbers on the RVA have been generated as a contiguous group of 256 addresses, the LCU can be calculated from the last two digits of the device number. For example, for devices with an address between A40 and A7F, the corresponding LCU is LCU1. Table 2 shows the relationship between the device numbers and LCUs.

5.6.2	Determining the Channel Connection Address
	The CCA on an RVA is relative to the LCU and is always between 00 and 3F. If
	the device numbers have been generated as a contiguous group of 256
	addresses, the CCA can be calculated from the last two digits of the device
	number as shown in Table 2. For example, for device numbers AC0 through
	AFF, subtract x′C0′ from the last two digits of the device number, and the
	corresponding CCAs are 00 through 3F.
Table	2. Determining LCU and CCA Values for the RVA
	Device Number	Logical Control	Channel Connection Address
		Unit Number
	00 - 3F	LCU00	00 - 3F
	40 - 7F	LCU01	00	- 3F	(subtract x′40′ from device number)
	80 - BF	LCU02	00	- 3F	(subtract x′80′ from device number)
	C0 - FF	LCU03	00	- 3F	(subtract x′ C0′ from device number)

Chapter 5. Peer-to-Peer Remote Copy 39