Remote Operation
Status Byte
The Status byte register contains the STB and RQS (MSS) messages as defined in 488.1. You can read the status byte register using a 488.1 serial poll or the 488.2 *STB? common command.
The *STB? query causes the device to send the contents of the Status Byte Register and the Master Summary Status (MSS) summary message. The *STB? query does not alter the status byte, MSS, or RQS.
Table 5-9 Status Byte Summary Register
Bit | Bit |
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| Weight | Bit Name | Description |
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0 | 1 | Reserved | Reserved |
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1 | 2 | Reserved | Reserved |
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2 | 4 | Error/Event Queue | Set if any errors are present in the Error/Event queue. |
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| (ERR) |
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3 | 8 | Questionable Status | Set if any bits are set in the Questionable Status Event |
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| Register (QSR) | register. |
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4 | 16 | Message Available | Indicates whether the output queue is empty. MAV is |
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| (MAV) | TRUE if the device is ready to accept a request from the |
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| controller. |
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5 | 32 | Standard Event Status | A summary of the Standard Event Status Register. |
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| Bit Summary (ESB) |
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6 | 64 | Request Service (RQS) / | Not Implemented / MSS indicates that the device has at |
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| Master Status Summary | least one reason for requesting service. |
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| (MSS) |
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7 | 128 | Operation Status | Present if a bit is set in the Operation status register. |
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| Register (OSR) |
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Error/Event Queue (ERR)
This bit is TRUE if any errors are present in the Error/Event Queue.
Questionable Status Register Summary (QSR)
This bit is TRUE when a bit in the Questionable Event Status Register is set and its corresponding bit in the Questionable Status Enable Register is TRUE.