HT-CM400 NXP Semiconductors, HT-CM400 Datasheet - Page 11

• Manufacturer Part Number: HT-CM400
• Description: Ht Cm400; Ht Rm440 Family; Ht Rm800 Family Interface Protocol Reader - Host
• Manufacturer: NXP Semiconductors

98-02-10
Rev. 1.0
Communication Reader-Host
3.2 Ordinary Protocol
If only a single read/write device with a node address equal to zero is connected to the host (e.g.
on a RS232 serial line) the Ordinary Protocol is used to address this reader.
Format of the Ordinary Protocol (HOST READER and READER HOST):
Byte
1
2
3
4
......
n
Function Block Length
Block Title
data
data
.........
BCC
3.3 Extended Protocol
If more than one read/write devices with node addresses different from zero are connected to the
host (e.g. on a RS485 serial line) the Extended Protocol is used to address a single reader.
Format of the Extended Protocol (HOST READER and READER HOST):
Byte
1
2
3
4
......
n-1
n
Block Length
Block Title
data
data
.........
Node
BCC
Function
+ 0x80
Address
Differences to Ordinary Protocol: Bit 7 of Block Length is set, and the Node Address is inserted
just before BCC.
If a reader’s node address is different from zero, the reader enters net-mode. In this mode the
reader expects all commands from the host to be sent in Extended Protocol including the right
Node Address (except SetModuleAdr). If the host transmits a string that does not meet these
conditions, the command is ignored, and there will be no answer from the reader (whereas a
reader being not in net-mode - with node address equal to zero - would at least answer with a
SERIAL ERROR message).
The command SetModuleAdr is used to assign a unique node address to a device whose serial
number is known. This command should be sent in Ordinary Protocol. If the right serial number
was sent, there will be an answer from the read/write device. This answer is sent in Ordinary
Protocol if the former node address of the reader was zero, otherwise the answer is sent in
Extended Protocol.
For communication in Extended Protocol use commands with ‘Proloc_M’-prefix. For further
information see Header File PROLBMU6.h.
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Htswp.doc/HS