{"product_id":"ic821a","title":"Black Box Async RS232 to RS422\/485 Interface Converter - DB9 to Terminal Block","description":"\u003cp\u003eThe BLACK BOX® Universal RS-232 to RS-422\/485 Converter with Opto-Isolation isolates and converts RS-232 signals into RS-422\/RS-485 signals and vice versa. Unlike other converters, external software is not required to control data flow. The RS-232 input is wired for DCE through a DB9 female connector, and RS-422\/RS-485 signals are interfaced through a removable terminal block. To supply external power to the terminal block, you need our 120-VAC\/12-VDC Wallmount Power Supply (PS1003). \u003cbr\u003e\u003cbr\u003eFor RS-232, the connection requires RD, TD, and Signal Ground. \u003cbr\u003e\u003cbr\u003eIn RS-422 mode, the driver is always enabled for full-duplex communications. A twisted pair is required for transmit, and a twisted pair is also required to receive. A ground reference wire is also needed. Switch settings are Switch 1: RS-422; Switch 2: Echo On; Switches 3 and 4: 4 Wire. \u003cbr\u003e\u003cbr\u003eIn both RS-485 modes, the RS-485 driver is automatically enabled during each space state by the presence of an RS-232 signal. When the RS-232 data is in a mark or idle state, the RS-485 driver is disabled and the RS-485 data lines are held in a mark state by the bias provided by a 4.7-ohm resistor; the value of this resistor may need to be changed, depending on the termination you use. \u003cbr\u003e\u003cbr\u003eTo connect to several RS-485 devices with minimal wire, select the unit's 2-wire, half-duplex RS-485 mode. When data is requested, the addressed device transmits and then reverts back to receive status. Switch settings for this mode are Switch 1: RS-485; Switch 2: Echo Off; Switches 3 and 4: 2 Wire. \u003cbr\u003e\u003cbr\u003eFor 4-wire master\/slave circuits, select the unit's 4-wire, full-duplex RS-485 mode. In this mode, addressed devices can receive data while transmitting data from a previous request. When used as a master in a single-master system, Switch 1 may be selected because the unit is the only transmitter in the system. When used as an RS-485 slave, the RS-232 device must provide addressability. Biasing in a master\/slave system is provided by the end-of-line slave. Switch settings for this mode are Switch 1: RS-485; Switch 2: Echo On; Switches 3 and 4: 4 Wire.\u003c\/p\u003e","brand":"Black Box Corporation","offers":[{"title":"Default Title","offer_id":53878205808751,"sku":"IC821A","price":315.99,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0731\/6144\/1391\/files\/1013260734.jpg?v=1788288643","url":"https:\/\/power123.com\/products\/ic821a","provider":"Power Surge Technologies Ltd.","version":"1.0","type":"link"}