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BRI Logical Interface, Using Message Checksums

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Chapter 3 - Understanding BRI Programming Elements BRI Logical Interface The BRI is an RFID reader interface that uses this command/response structure: 1 An external host sends the reader a command. 2 The reader executes the command. 3 The reader responds to the host. Both the commands and responses use ASCII characters followed by a terminator. The default terminator is a carriage return/line feed () character sequence and can be changed if required. For help, see "TTY" on page 97. There is no timing associated with sending a command to the BRI. The BRI waits indefinitely for the command terminator before executing the command. Using Message Checksums Beyond the command/response terminators, you can also use message checksums to enhance the communication resilience between the external host and reader. All data sent to and returned from the BRI is returned as printable ASCII characters. Except for the command and response delimiters, these are by default, the XON and XOFF start and stop characters, or other non-printable ASCII characters as defined by the user. Certain applications may require an additional level of data verification. In order to provide an increased level of data integrity, you can enable a BRI attribute that allows message checksums to be added to data sent to and from the BRI. The checksum value is sent or returned as two ASCII-readable characters and represents a modulo 256 summing of the command or response, up to but not including the response delimiter characters. The checksum shall be calculated and then returned as two ASCII characters representing the hex value of the modulo 256 sum. The field separator character is inserted just before the checksum and is included in the checksum calculation. READ TAGIDA5 0123456789ABCDEFh 0A In this example, the checksum value for the response is 0x40A. The response checksum is returned as the two least significant characters of the modulo 256 calculated checksum. In this case, the characters 0 and A are returned. You enable both command and response message checksums when you enable the attribute CHKSUM. If a checksum error is detected on an incoming message, the BRI returns an error message CKERR to the host. For commands, the checksum is done on all characters up to the actual checksum itself. If you decide to put an ASCII space character before the checksum value, you must include that space character in the checksum calculation. 16 Basic Reader Interface Programmer Reference Manual

Section	Page
Before You Begin	11
Safety Information	11
Global Services and Support	11
Warranty Information	11
Web Support	11
Send Feedback	11
Telephone Support	12
Who Should Read This Manual	12
Related Documents	12
Chapter 1 - Introducing the Basic Reader Interface	13
Overview of the Basic Reader Interface	14
What’s New?	14
General Features of the BRI Architecture	14
Two Typical BRI Usage Scenarios	14
BRI TCP Applications	15
Choosing a TCP Port for an Application Using TCP	15
Resetting the Reader to the Factory Default Configuration	15
Identifying the Version of BRI on Your Reader	16
Conventions Used in This Manual	17
Chapter 2 - Designing Robust BRI Applications	19
Before You Begin Programming	20
Managing RFID Configuration	20
Using the RFID Resource Kit	21
Recommended Software Structure	21
Programming the BRI Message Layer	23
BRI Message Types	23
BRI Command Processor	24
BRI Asynchronous Event Handler	24
Response Handler	24
Programming the BRI Transport Layer	24
Transport Operation	24
Transport Initialization	25
Multi-Threaded Implementation	25
Chapter 3 - Understanding BRI Programming Elements	27
BRI Logical Interface	28
Using Message Checksums	28
Reserved Keywords	29
Keywords Reserved for BRI Commands	29
Keywords Reserved for Command Parameters	30
Keywords Reserved for Reader Attributes	32
Keywords Reserved for Reader Error and Success Responses	33
Constants	34
Data Field Definitions	34
ANTENNA	34
AFI	35
BIT(memory_bank:startbit, bits)	35
COUNT	35
EPCID	35
HEX(memory_bank:address, length)	36
INT(memory_bank:address, length)	37
ISOUII	38
PC	39
RSSI	39
STRING(memory_bank:address, length)	39
TAGTYPE	40
TIME	40
Data Conditions	40
Using Native Tag Selector Logic in Data Conditions	41
Using AND/OR Logic in Data Conditions	42
Using the AND and OR Keywords	43
Grouping Expressions Without Using Parentheses	44
Using EPCC1G2 Select Logic in Data Conditions	45
Multi-Protocol Condition Usage	46
Chapter 4 - BRI Commands	47
BRI Commands	48
ATTRIBUTE	48
Changing the Reader Attributes	48
Reading the Reader Attributes	50
BLOCKPERMALOCK	50
BLOCKPERMALOCK READ	52
BRIVER	52
CAPABILITIES	53
DIAGNOSTICS	56
ERASE	57
FACDFLT	57
FLEXQUERY	59
HELP	59
HWCC	60
HWID	60
HWPROD	60
HWREGION	60
HWVER	61
KILLTAG	62
LOCK	62
PING	63
PLATDFLT	63
PRESET	64
PRINT	64
PROTECT	64
READ	66
READGPI	72
REPEAT	72
RESET	73
SET	74
SWVER	75
TRIGGER	75
TRIGGERQUEUE	78
TRIGGERREADY	79
TRIGGERWAIT	80
VERSION	80
WRITE	81
WRITEGPO	85
BRI Extensions for NXP Tags	86
NXPALARM	86
NXPCONFIG	87
NXPEAS	87
NXPREADPROTECT	88
BRI Extensions for Fujitsu Tags	88
FJAREAREADLOCK	88
FJAREAWRITELOCK	88
FJAREAWRITELOCKWOPWD	89
FJBURSTERASE	89
FJBURSTWRITE	89
FJCHGAREAGROUPPWD	90
FJCHGBLOCKGROUPPWD	90
FJCHGBLOCKLOCK	91
FJCHGWORDLOCK	91
FJREADBLOCKLOCK	91
BRI Extensions for Impinj Monza 4 Tags	92
READ IMPINJQT	92
WRITE IMPINJQT	92
BRI Extensions for EM Microelectronics Tags	93
READ EMM_GETUID	93
READ EMM_GETSENSOR	93
WRITE EMM_SENDSPI	94
WRITE EMM_RESETALARMS	94
Generic Tag Access Command	94
ACCESSCMD	95
Understanding [READ FIELD] and [WRITE FIELD] Parameters	97
[READ FIELD] Examples	97
[WRITE FIELD] Examples	97
Understanding the <ATTRIBUTE NAME> Parameter	98
ANTENNAS or ANTS	98
ANTTIMEOUT	99
ANTTRIES	99
BAUD	99
BROADCASTSYNC	100
BTPWROFF	100
CHANNEL	100
CHKSUM	100
DENSEREADERMODE	101
ECHO	101
EPCC1G2PARAMETERS	101
FIELDSEP	101
FIELDSTRENGTH	102
IDREPORT	103
IDTIMEOUT	103
IDTRIES	104
INITIALQ	104
INITTRIES	104
LBTCHANNEL	104
LBTSCANENABLE	105
LOCKTRIES	105
NOTAGRPT	105
QUERYSEL	106
QUERYTARGET	106
RDTRIES	106
RPTTIMEOUT	107
SCHEDULEOPT	107
SELTRIES	108
SESSION	108
TAGTYPE	108
TIMEOUTMODE	109
TTY	109
UNSELTRIES	110
UTCTIME	110
XONXOFF	110
WRTRIES	111
Understanding the Timeouts and Tries	111
Setting IDTIMEOUT and ANTTIMEOUT	111
When IDTIMEOUT <= ANTTIMEOUT	111
When IDTIMEOUT > ANTTIMEOUT	112
Setting IDTRIES and ANTTRIES	112
When IDTRIES < ANTTRIES	112
When IDTRIES >= ANTTRIES	113
Setting INITTRIES	114
Understanding the [LITERAL] Parameter	115
Reading and Writing STRING Fields	115
Understanding ACCESS and KILL Passwords	116
Memory Bank 3 User Memory	117
Memory Bank 2 TID Memory	118
Memory Bank 1 EPCID Memory	119
Memory Bank 0 PASSWORD Memory	120
Understanding Error and Success Responses	121
Understanding EVENT Messages	122
Understanding the Format of BRI Command Responses	124
Creating and Using BRI Macros	125
Creating a Command Macro	126
Executing a Command Macro	126
Creating a Parameter Macro	126
Executing a Command With a Parameter Macro	127
Listing All Macros Stored in Memory	127
Displaying the Contents of a Macro	127
Deleting a Macro	127
Chapter 5 - Reader-Specific Platform Specifications	129
Reader-Specific Platform Specifications	130
ITRFxxx01 Readers	130
BRI Disabled by Default	130
Features Not Implemented	130
Buffer Sizes	130
Memory Management	131
Error Responses	131
Antennas	131
GPIO	131
Reader Attributes	131
BRI Commands	132
EVENT Responses	132
Phillips V1.19 TAG Type	132
Readers That Contain the IM5 Module	132
Buffer Sizes	132
Antennas	133
GPIO	133
Reader Attributes	133
FACDFLT Command	133
Readers That Contain the IM4 Module	133
WRITEGPI Command	133
READGPI Command	134
TRIGGER Command	134
Antennas	134
ANTENNA Data Type Definition	134
ANTENNAS or ANTS Attribute	135
Sensing an Over-Temperature Condition	135
Index	137
A	138
B	138
C	139
D	140
E	140
F	140
G	141
H	141
I	141
K	141
L	141
M	141
N	142
O	142
P	142
Q	142
R	142
S	143
T	143
U	143
V	143
W	143

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Chapter 3 — Understanding BRI Programming Elements

Basic Reader Interface Programmer Reference Manual

BRI Logical Interface

The BRI is an RFID reader interface that uses this command/response structure:

An external host sends the reader a command.

The reader executes the command.

The reader responds to the host.

Both the commands and responses use ASCII characters followed by a terminator.

The default terminator is a carriage return/line feed (<CRLF>) character sequence

and can be changed if required. For help, see

“TTY” on page 97

There is no timing associated with sending a command to the BRI. The BRI waits

indefinitely for the command terminator before executing the command.

Using Message Checksums

Beyond the command/response terminators, you can also use message checksums

to enhance the communication resilience between the external host and reader.

All data sent to and returned from the BRI is returned as printable ASCII characters.

Except for the command and response delimiters, these are <CRLF> by default, the

XON and XOFF start and stop characters, or other non-printable ASCII characters

as defined by the user.

Certain applications may require an additional level of data verification. In order to

provide an increased level of data integrity, you can enable a BRI attribute that

allows message checksums to be added to data sent to and from the BRI. The

checksum value is sent or returned as two ASCII-readable characters and represents

a modulo 256 summing of the command or response, up to but not including the

response delimiter characters. The checksum shall be calculated and then returned

as two ASCII characters representing the hex value of the modulo 256 sum. The field

separator character is inserted just before the checksum and is included in the

checksum calculation.

READ TAGIDA5<CRLF>

0123456789ABCDEFh 0A<CRLF>

In this example, the checksum value for the response is 0x40A. The response

checksum is returned as the two least significant characters of the modulo 256

calculated checksum. In this case, the characters 0 and A are returned.

You enable both command and response message checksums when you enable the

attribute CHKSUM. If a checksum error is detected on an incoming message, the

BRI returns an error message CKERR to the host. For commands, the checksum is

done on all characters up to the actual checksum itself. If you decide to put an ASCII

space character before the checksum value, you must include that space character in

the checksum calculation.