USFilter DEPOLOX 3 PLUS - Specification of Bus Interface; Transmission Protocol

IM 50.560CA UA (B/4-03)
DEPOLOX
®
3 PLUS RESIDUAL ANALYZER
58
3.7.3 Specification of Bus Interface
1 Synchronization mode: Asynchronous
2 Transmission rate: 19200 Baud
3 Data format (asynchronous): - Start bit: 1 Bit
- Data bit: 8 Bit
- Parity bit: even
- Stop bit: 1 Bit
4 Signal polarity: Differential voltage interface
Logical “1” = (A-B >= 0.2V)
Logical “0” = (A-B <= -0.2V)
5 Handshake: No handshake because of request
control with fixed blocks
6 Transmission code: USF/W&T-Protocol (master-slave)
multipoint communication,
maximum 32 users
7 Galvanically not isolated
3.7.4 Transmission Protocol
For the communication between master (active user, e.g., computer) and
slave (passive user), two different kinds of frames are used:
• Request - Frame
• Set - Frame
The slave answers to these frames with the following frames:
• Answer frame
• Positive confirmation
• Negative confirmation
The bytes of these frames always have the same formats:
• 1 Start bit (always “0”)
• 8 Data bits
• 1 Parity bit (even)
• 1 Stop bit (always “1”)