Section 7. Bi-Directional Communications; Enquire/Ack/Nak - SATO E series Programming Manual

BI-DIRECTIONAL COMMUNICATIONS
This is a two-way communications protocol between the host computer and the
printer, thus enabling the host to check printer status. When Bi-Com 4
communications is selected, there is no busy signal from the printer. The host must
request the complete status from the printer, including ready/busy. The host may
request status in two different ways.

ENQUIRE/ACK/NAK

In the Bi-Com 4 mode, the host transmits an ENQ (05 hexadecimal) to the printer and
the printer will respond with its status within five milliseconds. If printing, it will respond
upon finishing the current label, then resume printing. In order for this protocol to work
properly with an RS232C Interface, pin 6 (DTR) and pin 5 (CTS) must be held high by
the host. One way to ensure these pins are always in the correct state is to tie pin 20
(DTR) to pin 6 (DSR) and pin 4 (RTS) to pin 5 (CTS) at the printer end of the cable.
ENQUIRE (ENQ)
Upon receipt of an ENQ command, the printer responds with 25 bytes of status
information bounded by an STX/ETX pair. The Bi-Com protocol works only in the Multi
Job Buffer mode. The status information is defined as follows:
<STX>{ 2 Byte ID}{1 Status Byte}{6 Byte Label Remaining}{16 Byte Job Name}<ETX>
• ID - This is a two byte number identifying the current print job ID. The print job ID
is defined using the <ESC>ID Job ID command transmitted with the print job
(see Job ID Store in the command listing for more information on how to use this
command). The range is from 00 to 99.
• Status - A single byte defining the current status of the printer (see the Status
Byte Definition table).
• Label Remaining - Six bytes defining the number of labels remaining in the cur-
rent print job. The range is from 000000 to 999999 labels.
• Job Name - 16 bytes of ASCII characters identifying the name assigned to the
job by the <ESC>WK Job Name command. If the Job Name is less than 16
characters, the field will be padded with leading zeroes.
If an ENQ is received after the print job specified in the ID bytes has been completed,
or there is no data in the buffer, the printer will respond with two "space" characters
(20 hexadecimal) for the ID number, six "zero" characters (30 hexadecimal) in the
Remaining Labels bytes and the 16 byte Job Name.
CANCEL (CAN)
If a CAN (18 hexadecimal) command is received , it will stop the print job and clear all
data from the receive and print buffers. A delay of five milliseconds or more is required
before any new data can be downloaded. The CAN command is effective immediately
SATO Programming Reference
SECTION 7.
Page 7-1