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INTRODUCTION
The SER-4485-SI-M is an industrial-grade RS-232/485 to optically isolated 4-port RS-
485 repeater/splitter/hub. This RS-485 hub is designed to expand a RS-485 channel in
the RS-485 network to four RS-485 channels. It has one RS-232/RS-485 upstream input
port and four independent downstream RS-485 output ports. Data received from the
input channel will be simultaneously transmitted to all the four downstream RS-485
channels. Data received from the downstream RS-485 ports is forwarded back to the
upstream port only, and is not sent to any other RS-485 ports in the loop. Each RS-485
output port is designed with an individual driver. The failure of any RS-485 ports in the
downstream loop will not affect the normal function of the other RS-485 ports to
ensure reliable operation.
The SER-4485-SI-M 4-Port RS-485 hubs can be added to RS-485 network to increase
the maximum nodes up to 512 nodes of RS-485 devices and to increase the
transmission distance more than 1.2km with stable and reliable performance.
The SER-4485-SI-M is optically isolated with 3000VDC optical isolation. The optical
isolation protects your PC or RS-485 devices from spikes and surges on the RS-485
network, by converting the electrical pulse into an optical signal and then changing it
back into an electrical pulse. Your computer or related RS-485 device is well protected,
since the surges and spikes cannot cross the optical link. The SER-4485-SI-M is
protected by surge protector to withstand electrostatic discharge and power surges
up to 600W. Surge suppression on all signals prevent from damages caused by
lightning or high voltage.
The SER-4485-SI-M provides failure warning and protected circuit for 4 independent
RS-485 output ports. It is an effective solution for the connection of multiple RS-485
devices and reliability enhancement. The failure warning and protected circuit can
suffice to protect the communication system. When any of the RS-485 ports has
incorrect signals or reversed connection, the protected circuit can breakdown the RS-
485 port automatically. The breakdown port will be isolated to ensure that other RS-
485 devices work normally. The user can locate the failed port or devices connected
using the failure indication LEDs.
