SUPER MICRO Computer MIIC-203 - Manual (Page 38)

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Master Read Message
This command causes iPort/AFM to read the specified number of data bytes from
the currently selected Destination I
2
C Slave Address with or without generating an
I
2
C Stop condition after the last byte is received.
Enter Byte Count (Decimal 0...32767) then Press Enter, or ESCape to Cancel.
A Byte Count of Zero (0) represents a Variable Length message, where the first byte
read from the I
2
C Slave device indicates the number of additional trailing bytes are
available to read. iPort/AFM automatically reads the first byte, then the additional
bytes as specified by the first byte. All message bytes including the Length byte are
returned to the Host computer.
The received text is a representation of the data bytes within the Master Receive
message. The format of this data is controlled by the current setting of the Hex Only
Display Control .
If the device acknowledges its I
2
C Slave Address, the specified number of bytes are
read from the current Destination I
2
C Slave Address. iPort/AFM acknowledges all
bytes read except the last. If not disabled, the message is then terminated with an
I
2
C Stop condition.
Sending Master Receive messages with No Stop allows the Master to retain
exclusive control of the I
2
C Bus until it finally sends a Stop. During this time, the
Master can send additional (Repeated Start) Master Transmit or Master Receive
messages to the same or other I
2
C Slave devices.
Command: /(*)Rnnnn[CR] 'Master Read Message
(* = No Stop)
Response 1: /MRCtext[CR] 'Master Read Complete
Response 2: /SNA[CR] 'Slave Not Acknowledging
Response 3: /I81[CR] 'iPort/AFM is Busy, Command Ignored
Response 4: /I83[CR] ' I
2
C Arbitration Loss Detected
Response 5: /I88[CR] 'iPort Connection Not Open
Response 6: /I89[CR] 'Invalid Command Argument
Default Setting: None