5.6.4Setting parameters
The user can specify the optimal operation mode for the user system environments by setting the following parameters with the MODE SELECT or MODE SELECT EXTENDED command:
∙Error recovery parameter
∙Disconnection/reconnection parameter
∙Caching parameter
∙Control mode parameter
With the MODE SELECT or MODE SELECT EXTENDED command, specify 1 for the "SP" bit on CDB to save the specified parameter value on the disk. This enables the IDD to operate by using the parameter value set by the user when power is turned on again. When the system has more than one INIT, different parameter value can be set for each INIT.
When the parameters are not set or saved with the MODE SELECT or MODE SELECT EXTENDED command, the IDD sets the default values for parameters and operates when power is turned on or after reset. Although the IDD operations are assured with the default values, the operations are not always optimal for the system. To obtain the best performance, set the parameters in consideration of the system requirements specific to the user.
This section outlines the parameter setting procedures. Refer to Chapter 3 of SCSI Logical Interface Specifications for further details of the MODE SELECT and MODE SELECT EXTENDED commands and specifying the parameters.
IMPORTANT
1.At factory shipment of the IDD, the saving operation for the MODE SELECT parameter is not executed. So, if the user does not set parameters, the IDD operates according to the default value of each parameter
2.The model select parameter is not saved for each SCSI ID of but as the common parameter for all IDs. In the
3.Once parameters are saved, the saved value is effective as long as next saving operation is executed from the INIT. For example, even if the initialization of the disk is performed by the FORMAT UNIT command, the saved value of parameters described in this section is not affected.
4.When the IDD, to which the saving operation has been executed on a system, is connected to another system, the user must pay attention to that the IDD operates according to the saved parameter value if the saving operation is not executed at installation.
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