Ulvac G-Tran Series, Manual

SK00-9663-E8-003-00 

RS-485 with terminating resistor (Example) 

Example) USB serial interface USB-485 manufactured by NATIONAL INSTRUMENTS. 

If the number of RS-485 connections is large, the total length of the connection 

cable is more than 15m, or communication errors frequently occur, install a 

terminating resistor in the terminating equipment. 

Standard data format 

The following is the standard data format for sending and receiving. 

: 

AD0 

AD1 

CMD 

D0 

…… 

Dn 

SH 

SL 

CHKH  CHKL 

CR 

: 

Colon 

AD0  Device address, higher 4bit (0

～

9) 

AD1  Device address, lower 4bit (0

～

9) 

CMD  Commands (upper/lower case-sensitive) 

D0 

Data 4bit (0

～

9, A

～

F) 

Dn 

Data 4bit (0

～

9, A

～

F) 

SH 

Higher bits of status (4bit) 

SL 

Lower bits of status (4bit) 

CHKH  Higher bits of checksum (4bit) (0

～

9, A

～

F) 

CHKL  Lower bits of checksum (4bit) (0

～

9, A

～

F) 

CR 

Carriage return 



Commands consist of alphanumeric uppercase and lowercase 

characters. 



The checksum is the exclusive OR sum (XOR) from AD0 to SL. 

Convert all in ASCII code hexadecimal. 

Host pin No.

This unit pin No.

RxD+

RS485+

12

4

8

TxD+

RS485-

10

GND

RS485+

13

RxD-

9

TxD-

5

15

1

GND

terminating

resistor

5