User`s manual

SH-300 Text Panel
Page 82 of 103
4.17 SH-300 Freedom Protocol
1. Communication configuration
SH-300 can communicate with some controllers via freedom protocol. When SH-300
communicates with controller via this protocol user need to define own controller freedom
communication format first. Here SH-300 is a master, controller is a slave. The request message
is sent from SH-300 and controller makes response message. Communication parameter is
shown as followIing:
Item Content
SH-300 COM port 9 pin COM port
Controller COM port Programming port
Default parameter
9600bps、8bits、1stop、None
Station No.
1-254 ,1 is Windows default
Distance (Max.)
15m/100m（twisted-pair）
Communication mode
RS232/485/422
Cable type
FREE-RS232/FREE-RS485/FREE-422
The freedom communication protocol takes byte as least addressing unit. And the most
addressing is in the range of 0-FFFFFFFF. The value of Register is stored with byte value. For
each Register, the first byte contains the high order bits and the second byte contains the low
order bits. Simultaneously one byte can be expressed as an eight-bit binary value which shows
each status of the 8 coils respectively. For example the Register B0 contains eight coil
address(M0-M7). That’s to say if you change the status of coil M0 up to M7. the value of Register
has been changed too. and if you change the value of Register ,the status of coil M have been
changed too. Therefore when you use this protocol you need to distribute the address between
Register and coil.
If Registers are addressed starting at B0, W0, DW0. Allocation map of memory address is shown
as following:
Register
address
Double
word
DW0 DW4 ……
word W0 W2 W4 W6
……
byte B0 B1 B2 B3 B4 B5 B6 B7 ……
Coil address
M0
∣
M7
M8
∣
M15
M16
∣
M23
M24
∣
M31
M32
∣
M39
M40
∣
M47
M48
∣
M55
M56
∣
M63
……
……