CT24 MCU
User Manual
51
9M02-7608-A001-EN
Version 2.0
7.7.1 REQUEST Function
MCUs are requested by an OCU. This is performed using a separate Request button in conjunction with the
position of an MCU selection on the OCU. The selection can be linked to one or more MCUs.
LRC OCUs have a rotary MCU selection switch.
All of the MCUs assigned to a selected switch position are always requested together.
MCUs assigned to an OCU as a result of a request remain permanently assigned to that OCU until released.
Additional MCUs may be requested by that OCU. Selected MCUs cannot be accessed by other OCUs.
Once one or more MCUs are requested, it is possible to switch between the various available combinations of
MCUs by altering the selection on the OCU.
7.7.2 RELEASE Function
The Release button is used to release the MCU(s) currently selected by an OCU.
An OCU can only release MCUs which it has previously requested. Conversely, MCUs not assigned to a specific
OCU cannot be released by that OCU.
One or multiple MCUs can be released at the same time. The MCU can be set to automatically release.
7.8
Sub Address Capability
This optional feature is available for the LRC-L OCU and the MMCU4 or CT24 MCUs.
It allows one LRC OCU to have secure and simultaneous selection of up to four from a larger number of MCUs by
the insertion into the OCU of a number of RFID keys.
With this feature, there is no possibility that any two OCUs can attempt to select the same MCU at the same time.
An example of use is the sequential selection of MCUs in a process flow. Keys 1 and 2 might represent hoist units
1 and 2; Keys 3 and 4 may represent sequential bridges; and the spare keys may represent further sequential
bridges.
Each of the selected MCUs can be enabled or disabled by an associated toggle switch.
There are three versions of SAC defined in the following ways:
•
One OCU may select 4 out of 512 MCUs
•
One OCU may select 3 out of 4096 MCUs
•
One OCU may select 2 out of 262,144 MCUs
7.8.1 T-SAC TransKeys
The identities of the selected MCUs are input by a secure, red RF TransKey inserted into a dual holder on the left
and right faces of the OCU. An OCU has the option of two or four slots and either two or four associated toggle
switches.
Two storage slots on the rail can hold unused keys.
7.8.2 B-SAC
Optionally, it is possible to use digital inputs in the OCU to select up to eight MCUs.
