RS485 Signal Amplifier Distant Extender Booster

Description:

GC-101 two-way buffer isolated RS485 hub is a communication device that supports two-way RS485 master station equipment and one or more RS485 slave station equipment. It is used to solve the problem of communication conflict when two master stations communicate with slave stations at the same time. Master station 1 queries slave station data will only return to master station 1 but not to master station 2. Master station 2 queries slave station data will only return to master station 2 but not to master station 1. Photoelectric isolation technology is adopted between the interface of master station and slave station to protect the equipment of master station from interference. The circuit is designed with 15KV ESD protection and 5KA lightning surge protection devices, which can effectively isolate
Harm of Lightning Static Electricity to Equipment Each of the three communication interfaces has a communication indicator lamp, which can visually see the state of each communication port The communication format and baud rate of transparent data transmission between master station and slave station interface can be set by software.


This product is suitable for automatic control system, monitoring system, alarm access control system, IC card charging, meter reading, one card parking lot charging and other comprehensive RS485 communication system.

Functional characteristics:

• The power supply input DC9-36V has overcurrent and reverse connection protection
• Support communication between two RS485 master station devices and one or more RS485 slave station devices
• Baud rate communication format can be set
• The signal interface has electrostatic lightning surge protection
• Communication and power supply are completely isolated between master and slave station interfaces
• The baud rate of 32-bit MCU and high-speed optocoupler can reach 115200
• The slave station communication port supports up to 120 nodes

Parameters:
Model: GC-101
Interface characteristics: compatible with EIATIA RS - 485 standard
Transmission medium: twisted pair or shielded wire
Working mode: asynchronous half-duplex (RS-485 two-way communication)
Communication protocol: transparent transmission without protocol restriction
Communication format: check bit of standard communication format is optional
Working power supply: 9 - 36VDC
Static power consumption: 0.6W
Signal indication: four indicators, status (STA), slave station (SLA), master station 1 (MA1), master station 2 (MA2)
Isolation degree: isolation voltage 2500Vrms 500VDC continuous, built-in DC/DC module
Baud rate: 1200bps-115.2Kbps
Protection grade: 600W lightning surge protection for each line of RS-485 interface at both ends,+15KV ESD protection
Transmission distance: 0-3000 meters (115200bps-9600bps)
Product size: 98x50x31mm (including both ends)
Operating environment: - 40 ° C to 85 ° C, relative humidity 5% - 95%

Resolve data conflicts when two masters communicate with one or more slaves

The communication between two 485 master stations and one or more slave stations requires an additional cache 485 hub Hub can automatically switch two master stations to communicate with slave stations to avoid communication failure caused by data conflict

Communication speed
1. First of all, it is explained that the communication speed is mainly related to baud rate and data length:
The higher the baud rate, the shorter the data length and the faster the communication speed; On the contrary, the slower the speed
In addition, it also depends on the response speed of the slave station. The faster the response speed of the slave station, the higher the overall communication speed will be

2. Using MODBUS protocol to read 11 registers at 9600 baud rate as an example:
Host computer query instruction
01 03 00 00 00 0b 04 0d
Lower computer response instruction
01 03 16 00 D7 00 6F 00 63 00 42 00 3700 60 00 23 00 4E 00 42 00 60 00 02 A8 D8
As shown in the figure, the sampling picture measured by oscilloscope can be
(1) The whole communication process takes about 100ms
(2) The time consumption of module forwarding (one receiving and one sending) is about 38ms

Troubleshooting
1PCB is not powered on, indicator light is not on, check whether the power cord is connected correctly, whether the positive and negative poles are connected, reverse use multimeter to measure whether the power supply voltage is correct, and the red indicator light on the PCB will always be on after troubleshooting

2 Unable to communicate check whether the communication port 485 line is connected backwards. Each communication channel should have an indicator light to receive correct data. The indicator light flashes. If there is no flashing, check whether the communication format and baud rate of the hub are consistent with the master station and slave station. If it is impossible to determine, the parameters can be reset to restore the default value