Allflex AFX-100 Uživatelský manuál stáhnout pdf (Strana 53)

Rev Australasia V2.3 12/04

53 53

4. Bus Protocol

Serial bus communication is active when serial port type is set to either RS422 or RS485.

The reader accepts in this mode framed as well as unframed (RS232 port type typical, as

described in section 3. ASCII protocol) commands. Readers responses to both framed and

unframed received commands are always framed.

Up to 32 readers can be addressed on the bus. Therefore each reader on the bus has to have

a unique bus address assigned! The Allflex Panel Reader does not respond to received

frames containing a different address than the own!

The data part of the framed message is equal to the ASCII protocol described in section 3.

Commands can be issued enclosed in the frame.

The reader in bus mode does not automatically send tag reading results! These are

temporarily stored in ID code buffer and can be requested by use of the command r

(described in section 3.2.13.). This command requests the first ID code stored and clears

the record upon transmission. The first tag data will be overwritten with new tag data once

the buffer is full without indication.

Command responses in bus mode lack initial and ending carriage return and line feed

characters!

4.1. Framing

The Allflex Panel reader uses a simple framing. Each message begins with SOH (02h),

followed by the binary reader address

, a STX (03h), the data and as the terminating

character an EOT (04h).

| | | | |

| | | | +--> End of Text (04h)

| | | +-----------> Data, as described in section 3. ASCII protocol

| | +---------------------> Start of Text (03h)

| +----------------------------> Readers bus address (00h to 1Fh)

+-----------------------------------> Start of Heading (02h)

Please see section 3.2.11. on how to change the serial

bus address.

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Allflex AFX-100 Uživatelský manuál Strana 53