Eurotech PCN-1001, User Manual

Page: 81 / 118

Test
an RS485 connection and use the RS485_GUI PCN-1001 User manual
81
PCN-1001_UserMan_En_4.0
Example of RS485 network
Several PCN-1001 devices can be connected in a Multi-drop RS485 two-wire half-duplex setup, see the diagram
below. In this configuration:
• You need a Host PC that acts as Master device, manages the RS485 network, and has ID number = 1
• Each one of the PCN-1001 devices must have same values for Baud Rate, Data Bits, Parity and Stop Bits,
but different ID number, starting form 2.
The Host PC starts the communication and includes the address of the target PCN-1001 within the SNP (Small
Network Protocol, see the paragraph ‘ The communication protocol’ on page 87).
All the PCN-1001 devices receive the command but only the target PCN-1001 will respond.
Note:
In Wide-Gate Configuration the Host PC sees only the first PCN-1001 of each group of counters in and the
address has to be assigned only to this one.
Fail-safe resistor 562 Ω (*)
Fail-safe resistor 562 Ω (*)
Termination resistor 133 Ω (*)