VK204-25-422-E Matrix Orbital, VK204-25-422-E Datasheet - Page 30

• Manufacturer Part Number: VK204-25-422-E
• Description: VF CHARACTER DISPLAY 20X4 RS422
• Manufacturer: Matrix Orbital
• Series: LK204-25r

Specifications of VK204-25-422-E

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5. Dallas One-Wire
5.1. Search for a One-Wire
Sends a search query to each of the up to 32 devices on the one wire bus. Any connected device will respond with
an identification packet.
Response
5.2. Dallas One-Wire
Performs a single Dallas 1-Wire transaction. Consult your device documentation for information regarding device
specific protocols. If an error is encountered, a corresponding value will be returned by the device.
Flags
Send Bits
Receive Bits
Data
Device
Transaction
Bit
7
6
5
4
3
2
1
0
Table 21: Dallas One-Wire Flag Table
14 bytes, identification packet as shown below
1 byte, flags for transaction, see below
1 byte, number of bytes to be sent to the device
1 byte, number of bytes expected to be received from the device
Variable, data to be transmitted LSB to MSB
Reset Bus prior to transaction
Read CRC8 from transaction
Add CRC8 to transaction
0 (Future Compatibility)
0 (Future Compatibility)
Flag Description
Offset
Dec
Hex
13
0
2
3
4
5
Unused
Dec
Hex
254 200 1
Length
FE C8 01
2
1
1
1
8
1
Table 20: Dallas One-Wire Packet Information
254 200 2
FE C8 02
Value
9002
138
10
49
Flags Send Bits Receive Bits Data
Flags Send Bits Receive Bits Data
0
0
CRC8 address check (0 indicates validity)
Another device packet will follow
Error Code (0 indicates success)
Last device packet
Device Address
Packet Type
Description
Preamble
Table 22: Dallas One-Wire Error Table
Code
0
1
2
3
Unknown Command
No Devices Found
Fatal Search Error
Error Description
OR
Success
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