ESP Safety UPES-50D, Operating Manual, Page: 36 / 51

36
UPES and PC Exchange Protocol
UPES exchange protocol
Software Version 3.22.04
2 wire RS-485 line.
MODBUS-RTU.
Data read command 3 or 4. Maximum requested number of words for one query does not exceed
32 .
Word write command 6.
Checksum — CRC16.
Byte structure:

8 information bits;

no parity;

1 stop bit;

Baud rate: 4800, 9600, 19200, 57600, 115200.
Table 1.
Parameter
Word
address,
hex
Data
type
Details
Modbus address (R/W) 0x0000 BYTE Lower byte – device Modbus address, 1–247
Device exchange rate
(R/W)
0x0001 BYTE
Lower byte – exchange rate with the top
level. For the two ports the same rate is set:
2-4800 baud;
3-9600 baud;
4-19200 baud;
5-57600 baud;
6-115200 baud.
Software Version
(R)
0x0002
–
0x0003
BYTE
High word:
lower byte – version number.
Low word:
high byte – subversion number 1;
lower byte – subversion number 2.
Example: 3.21.01
3 – version number;
21 – subversion number 1;
01 – subversion number 2.
Setting 1 card
(R/W)
0x0004 BYTE
High byte – communication mode:
0 – 1 port;
1 – 1 port with hot stand-by;
2 – ring;
3 – two independent ports.
Lower byte – exchange rate of two ports with
sensors:
0 – 1200;
1 – 2400;
2 – 4800;
3 – 9600;
4 – 19200.