PCI-485I2 2 端口、串行接口板

Description

PCI-485I2      2 端口、串行接口板

PCI-485I2    2 端口、串行接口板

Pci-485/2 (Part number: 777641-02) is a dual-port, non-concurrent serial communication card for PCI bus PCS. They are 6.5 inches (165 mm) long and may be introduced into PCI-Z, 5V PCI, or 3.3 slots. Each free port supports RS-485 adjusted mode transmission/collection, as well as single-ended transmission/collection. Each port of PCI-485/2 can contain a bias voltage. In this model, to guarantee communication, RS-485 should provide the bias voltage required for one transmitter in the frame, with the aim of providing a known “zero” state when all transmitters are off. In addition, receiver communication at each end of the system should end to avoid ringing. PCI-485/2 supports these options through the jumper method on the card.

In PCI-485/2, the 16550 UART type is used as an alternative communication component. A 16-byte transmit/receiver FIFO buffer is integrated into the instrument, designed to ensure that no information is lost in the multitasking framework while maintaining 100% similarity to the first IBM serial port. In this instrument, the user will find a crystal oscillator on the card that achieves an accurate baud rate higher than 115,200. The maximum baud rate on the NI PCI-485/2 is better than 460,800 baud and can be achieved by changing the jumper on the card. The driver/receiver type used is 75ALS180, which is suitable for driving very long communication lines at high baud rates. If there is a problem between communications, the drive/receiver has a thermal shutdown function. When the card is used for the first time, the working framework should automatically identify and arrange two COM ports for timely use.