Chroma 62000L Series User Manual page 86

Programmable DC Power Supply 62000L Series User's Manual
example, 24 (8+16) will be returned when querying the status of the Status Byte register,
QUES and MAV conditions have occurred.
In addition, the Status Byte Enable register will be cleared under the following conditions.
 Execute *SRE 0.
 Turn on the power and previously configured the power supply with *PSC 1.
Note If previously configuring the power supply with *PSC 0, the enable register won't
be cleared at power-on.
4.3.2.3.1 Read Status Byte Request
The power supply implements a 488.2 USB488 interface and the host may read the Status
Byte summary register at any time with the READ_STATUS_BYTE request. If the power
supply receives a READ_STATUS_BYTE request from the host, an USB488 Interrupt-IN
packet as shown as the following table.
Offset Field
0 bNotify
1 bNotify
4.3.2.3.2 Service Request (SRQ)
When the request service bit (RQS, bit 6) in the Status Byte is set, an USB488 Interrupt-IN
packet due to a SRQ condition is queued to send to the host. Select which summary bits will
generate the service request by setting the Status Byte enable register with *SRE command.
If the response is queued, the Status Byte is modified in the same way an IEEE-488.2 device
modifies the Status Byte after a SRQ/serial poll sequence. This means the power supply will
clear the RQS bit of the Status Byte register after a Status Byte (with RQS set) is queued to
be sent on the Interrupt-IN pipe.
The request service (RQS) bit is cleared only by queuing a response Interrupt-IN packet due
to the SRQ condition or by reading the event register whose summary bit is causing the
service request.
Offset Field
0 bNotify1 1
1 bNotify2 1
In addition, the following procedures present how to generate an SRQ interrupt.
 Clear the output queue of the power supply.
 Use *CLS to clear the event registers.
 Use *ESE to set up the enable masks of Standard Event register. Use the command *SRE
4-22
Size Value
1 Bitmap D7
D0~D6
Status The IEEE-488.2 defined Status Byte returned during a
1
Byte serial poll.
Size Value
Bitmap D7
D0~D6
Status The IEEE-488.2 defined Status Byte returned during a
Byte serial poll.
Definition
Must be 1. See the USBTMC specs.
The bTag value must be the same as the
bTag value in the READ_STATUS_BYTE
request.
Definition
Must be 1. See the USBTMC specs.
bTag. The bTag field must be 0x01.