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ID-01 Laser Scanner User’s Manual
Interface Standards
Polling Sequence
Data that is transmitted to the host (symbol data, noread messages, counters, etc.) via
concentrators is solicited by poll requests from the host.
The polling sequence example is by poll address 1E (ASCII hex value for Scanner 02)
and a REQ (request). The scanner responds by first transmitting its own address, 1E,
followed by a STX (start of text) character, and then the data. Next it transmits an ETX
(end of text) character and an LRC (longitudinal redundancy check) character.
If the concentrator (or controller) receives the data from the scanner and is able to validate it
with an LRC calculation, it responds with an ACK (acknowledgment). If the scanner in turn
receives the ACK, the scanner ends this exchange with a RES (reset).
Polling Reset
• If the scanner has no information, it responds to a poll request by transmitting a RES
(reset).
• If the scanner receives a NAK instead of the ACK after transmitting its data string, it will
re-attempt to send the data string up to three times. If the scanner still does not receive
an ACK, it will send a RES (reset) and discard the data in its buffers.
• If the scanner transmits data to the concentrator and the concentrator responds with an
ACK or NAK, but the scanner doesn’t receive the concentrator’s response, the scanner
will timeout and send a REQ to the concentrator and request another response. If after
three retries (the number of times it transmits a REQ to the concentrator) the scanner
receives no response, it ends the transmission with a RES (reset).
Concentrator
RES 1E REQ
ACK
Scanner 02
1E STX DATA ETX LRC
RES
Start of Sequence
End of Sequence
Polling Sequence
Summary of Contents for ID-01
Page 1: ...ID 01 Laser Scanner User s Manual ID 01 User s Manual ...
Page 12: ...xii ID 01 Laser Scanner User s Manual ...
Page 24: ...1 12 ID 01 Laser Scanner User s Manual Configure the Scanner ...
Page 58: ...3 20 ID 01 Laser Scanner User s Manual Intercharacter Delay ...
Page 78: ...4 20 ID 01 Laser Scanner User s Manual Scanner Setup ...
Page 82: ...4 24 ID 01 Laser Scanner User s Manual Laser Setup ...
Page 110: ...5 28 ID 01 Laser Scanner User s Manual Symbol Ratio Mode ...
Page 156: ...8 10 ID 01 Laser Scanner User s Manual Service Message ...
Page 164: ...9 8 ID 01 Laser Scanner User s Manual Auto Frame ...
Page 170: ...10 6 ID 01 Laser Scanner User s Manual Terminal Window Menus ...
Page 190: ...11 20 ID 01 Laser Scanner User s Manual Scanner Status Requests ...
Page 222: ...A 32 ID 01 Laser Scanner User s Manual Glossary of Terms ...