VC890 Protocol Rev 1.3 1. 2013-1-4 RS-232 Serial Interface SettingBaud rate is 9600 bits No parity 1 start bit 8 data bits (LSB first) 1 stop bit Notes: VC890 will transfer one set of data only if PC sends out 0x5e to command the data from it, if not, no data from VC890 will be transmitted. 2.1 OLED Display Figure below is the screen print of the OLED display of the VC890 device. that will be described in the following document.
. 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.
.2 Live Data For the Live Data message, the payload of the message contain the corresponding values with the current measurement mode of the DMM, where it can be separated into DMM Function, Display 1, Display 2, Display 3, Display 4,Display5,Display6and Status. Header Length The message format is shown as in the following table.
at different measurement mode.
Status: Msg[56] – Msg[63] The status of the DMM is stored at 7 different bytes of the live data message.
0 0 1 1 log_VOID_flag Loz_flag Hv_Warning_flag Auto_power_flag log_VOID_flag: This bit becomes 1 ,OLED show “VOID” symbol. Loz_flag This bit becomes 1 if the function is LOZ Warning_flag: This bit represents the super high voltage measurement warning. This bit becomes 1 if super high voltage measurement is active. Auto_power_flag: This bite represents the auto power off status of the DMM.
Msg[63].bytes&0x34 = 0x32;misplug EEROR ON A INPUT Msg[63].bytes&0x34 = 0x33;misplug EEROR ON V INPUT Memory_Overwrite_flag: Memory Type: Overwrite 3.3 Comp Data For the Comp Data message, the payload of the message contain MAX，MIN，COMP value of the stored at the DMM The message format is shown as in the following table. The value of MAX and MIN are represented in ASIC-II format. value at Inner/Outer mode is 0x00 at Inner Mode, and is 0x01 at Outer Mode.
PC at the following message format. Header Length The value at DMM Function is the same as the Live Data message.
Msg[39]:LOGGER DTAT DISPLAY 0x30: ON 0x31: OFF Msg[41] - Msg[40]:LOGGER SAMPLING RATE(1S~10S) Msg[42]:AUTO BRIGHTNESS 0x30: ON 0x31: OFF Msg[43]:BATTERY TYPE 0x30: ALKALINE 0x31: LI-AKKU 3.7 Result This message indicates the data transmission result of the message that required handshaking for guarantee of successful data exchange between PC and DMM.
Command is the command that send from the PC application to the DMM. on the command type that sent. The length of the command is depending Command may include data to change the setting of the DMM. Data Data contain setting information to the DMM from the associated command.
3 0x71 Set APO Time：30 min NO 114 0x72 Set APO Time：off min NO 94 0x5e PC→VC890 Send Current Value NO 98 0X62 Enter Data Log Set (SET MENU 3) NO 99 0X63 OLED Display Off After 5mins’ Data Log NO 100 0X64 OLED Display On After 5 mins’ Data Log NO 101 0X65 Memory Type: FIX NO 102 0X66 Memory Type: OVERWRITE NO 103 0X67 Continuous Sample Time YES 104 0X68 Exit Data Log Set (SET MENU 3) NO 105 0X69 Enter Other Set (SET MENU 4) NO 106 0X6A OLED Brightness Level 1 E
Header Length Command High Value Check Sum 2 Byte 1 Byte 1 Byte 7 Byte 2 Byte Msg[0]- Msg[1] Msg[2] Msg[3] Msg[4]- Msg[11]- Msg[10] Msg[12] 4.2 SET_COMP_MODE_LOW_VALUE This message contains the low value of the comparison mode. The low value is represented in ASIC-II format. Header Length Command Low Value Check Sum 2 Byte 1 Byte 1 Byte 7 Byte 2 Byte Msg[0]- Msg[1] Msg[2] Msg[3] Msg[4]- Msg[11]- Msg[10] Msg[12] 4.
Header Length Command Result Check Sum 2 Byte 1 Byte 1 Byte 1 Byte 2 Byte Msg[0]- Msg[1] Msg[2] Msg[3] Msg[4] Msg[5]-Msg[6] The result byte has the following value: 0x00 “Successful” 0x01 “Error-Resend-Previous-Message” 0x02 “Error-Do-Nothing”
