Quatech DSCLP-300, SSCLP-300 Termination Resistors, RS-422/485 Line termination resistance values

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7.6 Termination Resistors

Line termination resistors are provided for the input signals of each of the DSCLP-200/300's RS-422/485 ports. Termination may be selected or removed for individual signal lines using jumper blocks J6-J9.

RS-422 Rt = 100 ohm 1/2W

RS-485 Rt = 120 ohm 1/2W

RS-422/485 Receiver
+		RXD+	AUXIN+
	Rt		or

-		RXD-	AUXIN-

Jumpers J6-J9

2	4	2	4	2	4
1	3	1	3	1	3
	no termination	RS-422 termination		RS-485 termination
			(100 ohms)		(120 omhs)

(factory default)

Figure 21 --- RS-422/485 Line termination resistance values

DSCLP/SSCLP-200/300 User's Manual

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Contents DSCLP/SSCLP-200/300 Warranty Information Iii Standards to which Conformity is Declared Manufacturers NameManufacturers Address Application of Council DirectiveBase Address and Interrupt Level IRQ Hardware ConfigurationHardware Installation Address Map and Special Registers RS-422 or RS-485 Signal Line TerminationHalf-Duplex/Full-Duplex/Auto-Toggle Selection Page General Information Jumpers J6-J9 Full-duplex/Half-duplex Operation Signal ConnectionsRight Card Edge Jumpers Jumpers J10-J23 define the options for this card1 CTS0SEL, CTS1SEL J10 Clock Rate and Optional Registers Enable Scratchpad Register SPAD, J2Force High-Speed Uart Clock X2, X4, or X8 J3, 4 Clock multiplier jumper options Jumper/connector locations Hardware InstallationChannel Address Range Bit Description Enabling the Special RegistersInterrupt Status Register Dlab Bit Spad Jumper Register selected forQuatech Modem Control Register Quatech Modem Control RegisterBit Name Description Options RegisterWrite Read Clock Rate Uart Clock Maximum Data Multiplier Frequency Clock Rate MultiplierWindows Millennium Windows ConfigurationsWindows Windows Page Windows Windows NT Viewing Resources with Device Manager Two-Port RS-422/RS485 Serial Adapter Page DSCLP-200/300 Two-Port RS-422/485 Serial Adapter Page Page Page Page OS/2 Other Operating SystemsDOS and other operating systems QTPCI.EXE QTPCI.EXE Expert Mode display Jumper/Channel correspondence External ConnectionsRclk RTS/CTS HandshakeAUXIN/AUXOUT Loopback TclkHalf-Duplex/Full-Duplex/Auto-Toggle Selection Half/full-duplex and Auto-Toggle selection RS-422/485 Line termination resistance values Termination ResistorsRS-422/485 Peripheral Connection DSCLP-200/300 connector definitionsINTA# PCI Resource MapWith 64-byte FIFOs optional SpecificationsComputer will not boot up TroubleshootingCannot communicate with other equipment DSCLP/SSCLP-200/300