Overview 

There are some frequently asked questions about RS-485 configuration using the CoreStation (CS-40).

Here is a guide for RS-485 configuration with Device SDK Demo code using the CS-40. 


Three different RS-485 modes are supported as below.

  • Default: Factory default status for a device configuration.
  • Master: Devices can search and add slave devices through RS-485
  • Slave: Devices can be searched and added to a “Master” device through RS-485


The Slave device is not making a device match. It is just sending the credential input to a Master device, receiving the result, and showing it from the indicator or LCD display.


1.  Devices Used and Preparations 


- Programming Language: C# example code. (https://github.com/supremainc/BioStar2_device_SDK/tree/master/Example_Csharp/cli/csharp)


- Device: CoreStation, BioEntry W2


- Register users required for authentication.
** In this test, a Mifare CSN card was used.


- The physical wiring connections are as follows. 




If you want to learn more about the CS-40 and RS-485 wiring, please refer to the CS-40 guide on our website. (CoreStation Homepage Link)


If you want to learn more about the Daisy Chain and RS-485 connection, Please refer to this article:[Both BioStar] Daisy Chain and RS485 Connection



 2. How to configure RS-485 Master / Slave device using device SDK 


1. First, settings are required for the Slave device (BioEntry W2).

Configure the device mode to be used as a Slave. (ConfigControl.cs) 

Set the mode for the slave device. You can find which values to set in the document below.
(https://kb.supremainc.com/bs2sdk/doku.php?id=en:configuration_api#bs2rs485config)


Up to 31 slave devices can be connected through a daisy chain, and up to 8 fingerprint devices can be connected. 
But, if there's a need to make many fingerprint matching with multiple devices at the same time, it's recommended to use a limited number of slave fingerprint devices for optimal matching performance.


2. Settings are required for the CoreStation (CS-40).

2-1. Configure the device mode to be used as a Master refer to the step 1-2. (ConfigControl.cs)

 (You can skip this step since the CS-40 is only used as a Master.)


2-2. Get and Set the Slave Device.

First, connect to the master device. Search and add the slave device. (SlaveControl.cs)

CS-40: Use BS2_GetSlaveExDevice / BS2_SetSlaveExDevice API

All device(Except CS-40): Use BS2_GetSlaveDevice / BS2_SetSlaveDevice API


When the SDK is initialized, there are no information about the Slave devices. Therefore, a Slave device must be searched or added before controlling.


The authentication mode of the Slave must be changed while the Master is connected. The Slave device does not store the authentication mode separately.



3. After completing the configuration, test the Master / Slave device.   

Test using the credentials of the user on the Master device. The Slave device is just sending the credential input to a Master device. You can check authentication results by using a real-time monitoring log. (Log)