
PS2000A Datasheet
Doc. Number:
TECINHD001
Version 1.0
3/1/2002
P&S DataCom Corporation
26
10 Communication between PS2000A and Gateway
The communication between the PS2000A and network server is based upon the
MCUap
TM
1.0 protocol. The physical connection between the PS2000A and the server may be
RS-232, RS-485 or Modem.
10.1 Data Packet Structure
When the communication between the PS2000A and the network server adopts RS-232,
RS-485 or Modem mode, the format of the data packet is as shown in table 20.
Table 20 Communication Data Packet Used for PS2000A and Network Server
Character
Byte
Description
ESC
1
Escape (1Bh)
SOH
1
Start of Heading (01h)
ESC
1
Escape (1Bh)
SOH
1
Start of Heading (01h)
Data Packet
Header
Server_ID
4
Network Server Identification Code
Device_ID
8
Device Identification Code
State_Info
1
State Information Byte
Cmd
1
Command Byte
OBJECT_NAME
≤
13
Object Name String
Data0
1
Data 0
Data1
1
Data 1
Data2
1
Data 2
…
…
Data n-1
1
Data n-1
Data Packet of
MCUap Protocol
Application Layer
ESC
1
Escape (1Bh)
ETB
1
End of Transmission Block (17h)
Data Packet End
CRC
2
CRC Check Value
Check Word
N
OTE
:
I
F THERE IS A SYMBOL
ESC(0
X
1
B
)
IN THE DATA PACKET OF
MCU
AP
TM
PROTOCOL APPLICATION LAYER
,
A SECOND
ESC(0
X
1
B
)
SHOULD BE INSERTED
.
B
UT
CRC
CHECKOUT DOES NOT COUNT THE INSERTED
ESC.
The PS2000A allows the maximum length of the data packet to be 99 bytes at once,
transmitting or receiving. To establish the buffer size of the communication transceiver
used for the network server, the PS2000A should be set up according to the buffer size of
the MCU application system.
Only when the device identification code (Device_ID) is matching with the programmed
Device_ID in the PS2000A, can the PS2000A receive the data packet. Otherwise, the
PS2000A will not respond to the data from the network server.