User Manual

38 Quatech QTM-8524 Manual
4.4.2 Mode 2: Half-Duplex, Synchronous
Mode 2 enables communication between two or more QTM-8524 modules.
This allows a single QTM-8524 connected to a PC to communicate with
multiple other remote QTM-8524 modules also connected to PCs or PLCs. In
mode 2, a single QTM-8524 modules broadcasts signals to every other QTM-
8524 module in the network. These modules receive the information, inter-
pret the data, and respond accordingly.
Mode 2 requires all modules to be configured for half-duplex synchronous
communication. In a half-duplex system all QTM-8524 modules are jumper
configured for Slave State, and all must be configured for the same frequency
and baud rate. As in Mode 1, the synchronous network requires that data be
configured using the predefined data format noted in section 3.2.
Jumper Configuration:
1. No Channel Selection
2. Select Frequency from 2426.112 - 2458.26 MHz (Jumper 2)
3. Select Baud Rate from 600 bps to 57600 bps (Jumper 3)
4. Select Half Duplex Mode (Jumper 4)
5. Select Slave State (Jumper 5)
6. Select Synchronous Communication (Jumper 6)
7. Select RS-232 or RS-485 (Jumper 7)
(See Figure 2.4 for a diagram of QTM-8524 jumper settings.)
Advantages:
1. Decreases communication error rate
2. Increases communication stability
Limitations:
1. Fixed data format
2. Half-Duplex Only
3. Cannot be used with QTM-8000 Series I/O Modules