Ref.:19-4169-00 VK-2C RS-485 PROTOCOL OF COMUNICATION

Date: 02/06/2009

Hardware interface:

• RS-485. • 2 wires with a load of 1KΩ

Mode: • 9600 bauds. • 8 data bit. • 1 stop bit.

Information Request Command (4 bytes). Command that you have to send when you require information.

0xF0 VKDIR OC XOR

0xF0 start code. VKDIR VK address. OC Operation Code. XOR 0xF0 ^ VKDIR ^ OC

Possible Operation Codes (OC) 0x41 Read Al_C 0x44 Read Al_S 0x47 Read AL_A 0x4A Read the current weight. 0x4D Read the CELL value. 0x50 Read the CLAU value. 0x53 Read the CadE value. 0x56 Read the Zero value. 0x59 Read the Conf. 0x5C Read the Dir Value (Address) 0x5F Read the VK Status byte (*1).

*1 Status byte

B7 B6 B5 B4 B3 B2 B1 B0 BCD Error Code

0000 There is no Error 0001 Not well connected load cell 0010 Load cell positive overflow 0011 Load cell negative overflow 0100 Load cell Polarity error

AL_C 1= ON

AL_S 1= ON

AL_A 1 = ON

Hold 1= ON

Information Answer Command (5 Bytes). Information that you will receive if you send an information request command.

0xF0 VKDIR DataL DataH XOR 0xF0 start code. VKDIR VK address. Data L Low byte information Data H High byte information XOR 0xF0 ^ VKDIR ^ DatoL ^ DatoH VK Parameters load (6 bytes). Change the parameter information in the VK menu

0xF0 VKDIR ParamC DataL DataH XOR

0xF0 start code. VKDIR VK address. ParamC Parameter code (menu VK). DataL Low byte information. DataH High byte information. XOR 0xF0 ^ VKDIR ^ ParamC ^ DataL ^ DataH.

Possible Param. Codes (ParamC) 0x81 Write Al_C 0x84 Write Al_S 0x87 Write AL_A 0x8A Set PESO (weight). 0x8D Write the CELL value. 0x90 Write the CLAU value. 0x93 Write the CadE value. 0x96 Set Zero Operation. 0x99 Write Conf. 0x9C Write Dir Value (Address)

Parameter load Confirmation (1 Byte). (0xF3) Information that you will receive if you load a parameter

TIMING DIAGRAM

Command (Master) VK answer (Slave)

Byte 1 t1 Byte

2 t2 ..... Byte n tn ...tr... Byte

1 tb Byte 2 tb ..... Byte

n tb

t1, t2, ... tn = time that doesn’t affect VK. tr = Time between question and answer (10 msg recommended, 2 msg min) tb = Time of one bit.