Voltcraft VC-890 OLED DMM Digital Multimeter with Software included CAT IV 600V, CAT III 1000V VC890 OLED Guía De Información
Los códigos de productos
VC890 OLED
2.
Message from DMM to PC
The general format of the message sent from the DMM to the PC is represented as in the following:
Header
Length
Msg Type
Payload
Check Sum
2 Byte
1 Byte
1 Byte
TBD
2 Byte
Header:
Header is a two byte value indicating the beginning of the message. For device, the message header is always 0xABCD
regardless of the message type.
Length:
This value represents the length of the message that has to be handled. It is the number of bytes from Msg Type to
the last type of Check Sum.
Msg Type:
This value represents the type of message from the DMM to the PC, where there are 9 types of messages used for the
device, shown as the following table.
Msg Type
Value
Description
Device ID
0x00
The payload of this message contains the Device ID of the DMM
Live Data
0x01
The payload of this message contains the live of the DMM
Comp Data
0x02
The payload of this message contains the comparison mode setting of the DMM
NOCOMP
Data
Transfer
0x03
The payload of this message contains the NOCOMP data that are saved on the memory
COMP
Data
Transfer
0x04
The payload of this message contains the COMP data that are saved on the memory
SETUP
Data
Transfer
0x05
The payload of this message contains the SETUP data that are saved on the memory
Result
0xFF
The payload of this message contains the result of the data transmission for handshaking
purpose.
CheckSum:
16-bits check sum are added after the payload of the message. It is the sum of the byte values from the first byte of
Header to the last byte of Payload.
3.1
Device ID
For the Device ID message, the payload of the message contains the identity number of the DMM on the 20 byte value.
The Device ID is decoded on the PC with ASIC-II character string.
Header
Length
Msg Type
Device ID
Check Sum
2 Byte
1 Byte
1 Byte
20 Byte
2 Byte
Msg[0]- Msg[1]
Msg[2]
Msg[3]
Msg[4]-Msg[23]
Msg[24]-Msg[25]