GS a

ASB is the function that transmit the status of [cover open/close], [Online/Offline] from the printer automatically. It is called [ASB function] and the status is [ASB status]. If you use ASB, application can acquire the printer change in a real-time and passively.

Select any status enabled (except n = 0) and basic ASB starts. Then transmit the current basic ASB status. After that, while ASB is active the selected enabled basic ASB status is transmitted whenever the status changes.

When n = 0, basic ASB is disabled. When ASB is disabled, basic ASB status is not transmitted.

Multiple status items can be selected.

When ASB is active, ASB status is transmitted whenever the status changes even if the printer is disabled by ESC =.

This command setting is effective until ESC @ is executed, the printer is reset or power is turned off.

Any basic ASB status represents the enabled status whenever the status changes. Therefore the disabled status items may change, because each status transmission represents the current status.

The basic ASB statuses, corresponding to each bit for n are as follows:

n		ASB status
Bit	Function	Bit	Status
0	Drawer kick-out connector status	Bit 2 of the first byte	Drawer kick-out connector pin 3 status
1	Online/offline status	Bit 3 of the first byte	Online/ offline status
		Bit 5 of the first byte	Cover status
		Bit 6 of the first byte	Paper is being fed by paper feed button status
		Bit 0 of the second byte	Waiting for online recovery status
		Bit 0 and 1 of the third byte (∗1)	Roll paper near-end sensor status
		Bit 2 and 3 of the third byte (∗1)	Roll paper end sensor status
2	Error status	Bit 2 of the second byte	Recoverable error status
		Bit 3 of the second byte	Autocutter error status
		Bit 5 of the second byte	Unrecoverable error status
		Bit 6 of the second byte	Automatically recoverable error status
3	Roll paper sensor status	Bits 0 and 1 of the third byte	Roll paper near-end sensor status
		Bits 2 and 3 of the third byte	Roll paper end sensor status
6	Panel switch status	Bit 1 of the second byte	Paper feed status

Basic ASB status is 4-byte configuration [first byte – fourth byte].

First byte (printer information)

Bit	Binary	Status	Hex	Decimal
0	0	Fixed	00	0
1	0	Fixed	00	0
2	0	Drawer kick-out connector pin 3 is LOW. (∗1)	00	0
	1	Drawer kick-out connector pin 3 is HIGH. (∗1)	04	4
3	0	Online.	00	0
	1	Offline.	08	8
4	1	Fixed	10	16
5	0	Cover is closed.	00	0
	1	Cover is open.	20	32
6	0	Paper is not being fed by the paper feed button.	00	0
	1	Paper is being fed by the paper feed button.	40	64
7	0	Fixed	00	0

Second byte (printer information)

Bit	Binary	Status	Hex	Decimal
0	0	Not waiting for online recovery.	00	0
	1	Waiting for online recovery.	01	1
1	0	Paper feed button is not pushed (off)	00	0
	1	Paper feed button is pushed (on)	02	2
2	0	No recoverable error (except for autocutter error).	00	0
	1	Recoverable error occurred (except for autocutter error).	04	4
3	0	No autocutter error.	00	0
	1	Autocutter error occurred.	08	8
4	0	Fixed	00	0
5	0	No unrecoverable error.	00	0
	1	Unrecoverable error occurred.	20	32
6	0	No automatically recoverable error.	00	0
	1	Automatically recoverable error occurred.	40	64
7	0	Fixed	00	0

• Online recovery wait (bit 0) is changed when GS ^ is executed, the printer waits for the button to be pressed for removing a label, or roll paper to be replaced for some models.
• If recoverable error (bit 2) or autocutter error (bit 3) occurs due to paper jams or the like, it is possible to recover by correcting the cause of the error and executing DLE ENQ (n = 2).
• If an unrecoverable error (bit 5) occurs, turn off the power as soon as possible.
• The cause of the error can be checked by the offline response (when an offline cause is added). See GS ( H   <Function 49> .

Third byte (paper sensor information)

Bit	Binary	Status	Hex	Decimal
0, 1	00	Roll paper near-end sensor: paper adequate.	00	0
	11	Roll paper near-end sensor: paper near-end.	03	3
2, 3	00	Roll paper end sensor: paper present.	00	0
	11	Roll paper end sensor: paper not present.	0C	12
4	0	Fixed	00	0
5, 6	−	(Reserved)	−	−
7	0	Fixed	00	0

• Some paper sensors are not present, depending on the printer model. The names of some paper sensors are different, depending on the printer model.

Fourth byte (paper sensor information)

Bit	Binary	Status	Hex	Decimal
0 – 3	−	(Reserved)	−	−
4	0	Fixed	00	0
5, 6	−	(Reserved)	−	−
7	0	Fixed	00	0

During Block data [header – NUL] transmission, ASB is disabled temporarily. Therefore you cannot get the printer status change through ASB status when block data [header – NUL] is transmitted.

With a serial interface, the printer transmits a 4-byte ASB status message without confirming whether the host can receive data.

With a parallel interface, when ASB status is used, it is desirable for the host to be in a reverse idle state. However, if the host computer cannot always be in the reverse idle state, it is necessary to enter Reverse Mode regularly to watch for ASB status. If the host is not in the Reverse Mode for a long time, and the printer has to store ASB status changes to be transmitted, the following 2 sets (8 bytes) of ASB status are changed to special data and transmitted prior to other transmission data when the host enters Reverse Mode:

• ASB-1: Status information that shows whether status changes occurred
• ASB-2: The latest ASB status information

Basic ASB status can be differentiated by other transmission data by Bit 0, 1, 4, and 7 of the first byte. Process the transmitted data from the printer as ASB status which is consecutive 3 byte if it is "0xx1xx00" [x = 0 or 1]. However, the processing shown in the following is necessary in the identifying processing of ASB status.

• When the host communicates with the printer by XON/XOFF control, 4 bytes of data may interrupt ASB status; therefore, 4-byte code except for the XOFF code, is processed as ASB status. ASB status configuration is different from that of the XOFF code.