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Amplicon USB232U, Instruction Manual

The Amplicon USB232U is a powerful and reliable USB to RS232 converter. To ensure maximum functionality, we provide a comprehensive Instruction Manual that you can conveniently download for free from our website. Explore the full capabilities of the Amplicon USB232U with our easy-to-use manual at manualshive.com.

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USB232U/485Ui

 

 

 
 
 

 

Page 19 

either  (a)  a  packet  shorter  than  64  bytes  is  received  or  (b)  the  requested  data  length  is 
reached.  
 
The  performance  of  the  USB232U/485Ui  ports  is  therefore  not  exactly  equivalent  to  that  of 
legacy ports. For more information see the application note AN232-04 
 

4.3 

Testing and Troubleshooting 

 

If  the  installation  instructions  have  been  correctly  followed,  and  the  serial  communications 
interface is being used in conjunction with a proven software driver, then it is unlikely that any 
problems will be experienced in establishing communications through the serial interface. 
 
When difficulties do occur, the following notes may be helpful in isolating the problem area. 
 

4.3.1 

Testing with the Application Software 

 

If the port fails to install or behaviour is intermittent then the problem is probably to do with the 
USB connection and the following areas should be investigated. 
 

USB Cabling  Check the device has been correctly connected using a Type B USB 
cable. Check the cable is secure, and that the number of USB devices connected 
to the PC does not exceed 127. 
 
Device  Installation.  For  detailed  help  regarding  installation  of  these  devices  refer 
to 2.2 “Installing the Interface”. 

 
If the port successfully recognised and installed by the operating system and then the problem 
is probably on the serial communication side of the interface, and the following areas should be 
investigated. 

 
Communication circuits.  For  a  communications  circuit  to  operate  correctly,  both 
ends  of  the  circuit,  and  the  interconnecting  cables  must  be  serviceable  and  the 
correct  connections  made.  The  vagaries  of  RS232  implementation  often  cause 
problems in making the proper connections, and the manufacturers instructions for 
the equipment at each end should be carefully checked. 
 
Hardware handshaking control signals.  If the communication is operating under a 
software  handshaking  protocol  (X-ON,  X-OFF  etc.)  then  only  the  transmitted  and 
received  data  lines  need  to  be  connected.  If  the  application  requires  hardware 
handshaking by the use of control lines CTS, RTS, DSR, DTR or DCD, then these 
must be correctly interconnected or looped back, otherwise the program is likely to 
hang. 
 
Polarity  of  RS422/485  differential  data  lines.  Not  all  suppliers  use  the  same 
convention  for  the  polarity  of  the  differential  data  lines.  The  USB485Ui  lines  are 
labelled A and B for the transmitter and A' and B' for the receiver as defined in the 
RS422/485 specification. If the other device is labelled differently, then:- 
 

A

 is normally connected to 

A

 or 

A'

 or 

Y

 or 

High

 or 

+

 

B

 is normally connected to 

B

 or 

B'

 or 

Z

 or 

Low

 or

 –

 

 
If all devices are not so labelled and the polarity is not evident, or if a problem is 
suspected in this area, then some experimentation may be necessary. No damage 
should be done to the interface hardware by reversing polarity. 

Summary of Contents for USB232U

Page 1: ...ased product in a proper and efficient manner The information contained has been reviewed and is believed to be accurate and reliable however Amplicon Liveline Limited accepts no responsibility for any problems caused by errors or omissions Specifications and instructions are subject to change without notice USB232U 485Ui Instruction Manual Issue A2 Amplicon Liveline Limited Prepared by Helen Elco...

Page 2: ...OAD STOCKPORT SK3 8LF UK We declare that the product s described in this Instruction Manual perform in conformity with the following standards or standardisation documents Electro Magnetic Compatibility EMC EMC Directive 89 336 EMC CE Directive 93 68 EEC David Cooper MIEE Director MEV Limited ...

Page 3: ...n For Half Duplex Operation with Echo 7 2 3 1 3 Jumper Selection For Half Duplex Operation without Echo 7 2 3 2 Transmission Line Termination 8 2 3 2 1 Termination Resistors for RS422 485 Receivers 8 2 3 3 Jumper Factory Settings Summary 8 2 4 Application Software 9 2 4 1 Installation Testing 9 3 MAKING THE CONNECTIONS 10 3 1 External Connections 10 3 1 1 USB Connector 10 3 1 2 RS232 9 way Port 10...

Page 4: ...ATION i A 1 1 USB i A 1 1 1 Series B connector i A 1 2 USB232U RS232 Port ii A 1 2 1 9 way Connector ii A 1 2 2 Data Rate ii A 1 2 3 I O Protection ii A 1 2 4 ESD Protection ii A 1 3 USB485Ui RS422 485 Port iii A 1 3 1 9 way Connector iii A 1 3 2 Data Rate iii A 1 3 3 Rx I P Termination iii A 1 3 4 Tx O P Protection iii A 1 3 5 I O Isolation iii A 1 3 6 ESD Protection iii A 1 3 7 Modes iii A 1 3 8...

Page 5: ...Selection 8 Figure 2 5 Factory Jumper Setting Summary 8 Figure 3 1 USB Connector Termination Assignment 10 Figure 3 2 RS232 9 way Port Pin Designations 11 Figure 3 3 RS422 485 Amplicon Standard Port Pin Designations 11 Figure 4 1 Communications Standards Summary 16 Figure 4 2 RS422 Connected in Broadcast Mode 17 Figure 4 3 RS485 Connected in Multi Drop Half Duplex Mode 17 Figure 4 4 RS232 Loop Bac...

Page 6: ......

Page 7: ...the USB232U 485Ui Series of Data Communications Interfaces Each of the USB232U 485Ui series of interfaces is designed to meet stringent performance requirements and ease of use while maintaining compatibility with standard serial communications products USB 1 1 specification compliant Windows 98 2000 XP and Linux compatible Data rates selectable up to 1 M Baud RS232 and 3 M Baud RS485 FIFO modes s...

Page 8: ... serial port designed to meet one of the following standards RS232 full duplex serial port furnished with a 9 pin D type male connector conforming to IBM practice The port is fully configured with two data six control I O lines and one signal return RS485 full duplex half duplex multi drop operation or RS422 full duplex without RTS CTS control lines Depending on the application RS485 or RS422 oper...

Page 9: ...rom Amplicon Liveline Ltd contains 1 The USB serial interface as ordered in a protective bag The model will be one of the following and is identified by the type number printed on the PCB USB232U USB to RS232 Serial Communications Controller USB485Ui USB to RS422 485 Serial Communications Controller with I O signal isolation 2 The included distribution software and this manual on CD 3 Any addition...

Page 10: ...ests you have conducted You may also be asked if the operating system prompted you for a disk when you installed the device 1 4 4 Repairs If the unit requires repair then please return the goods enclosing a repair order detailing the nature of the fault If the device is still under warranty there will be no repair charge For traceability when processing returned goods a Returned Materials Authoris...

Page 11: ...USB232U 485Ui Page 5 Brighton East Sussex BN2 4AW England ...

Page 12: ... Windows 2000 Windows XP or Linux 2 2 Installing the Interface Connect a USB Type B cable between the USB232U 485Ui serial communications device and the host computer When the device is physically connected to the PC the Windows 98 2000 or XP operating system will discover new hardware From then on respond to the questions asked When prompted for a disk use the disk supplied Exact installation ins...

Page 13: ... the same serial lines 2 3 1 1 Jumper Selection For Full Duplex Operation Link Function JP2 2 3 JP3 2 3 Full Duplex 4 wire operation JP4 1 2 Receiver enabled when device is awake JP5 2 3 Transmitter enabled when device awake Figure 2 1 Jumper Settings For Full Duplex Operation 2 3 1 2 Jumper Selection For Half Duplex Operation with Echo Link Function JP2 1 2 JP3 1 2 2 wire operation TxA is connect...

Page 14: ...P1 2 3 Data line NOT terminated Figure 2 4 Jumper Settings for Termination Resistor Selection Further notes on RS422 and RS485 operation are given later in Chapter 4 Using the Serial Communications Devices 2 3 3 Jumper Factory Settings Summary The USB485Ui interface can be reset to its factory defaults by re configuring the device according to the following tables Link Function JP1 1 2 Data Line T...

Page 15: ...ce will operate in conjunction with all commercially available communications and data acquisition packages that support Windows 98 2000 and XP serial ports Install the required application software in accordance with the vendor s instructions assigning communications to the required COM port 2 4 1 Installation Testing Many applications packages include a self test feature and when the hardware an...

Page 16: ...ector Termination Assignment 3 1 2 RS232 9 way Port Connections to the RS232 are made via 9 way D type connectors on the interface The on board connectors are male and the mating sockets are available as accessories Provision is made for securing by screw jacks The 9 way D type connector pin out conforms to the industry standard and will support commercially available cables and adapters 5 9 4 8 3...

Page 17: ...Each connector is equipped with two or more different ground connections and care must be taken in the use of these grounds and the cable design to ensure that the EMC requirements are met and that isolation integrity is maintained in the case of the devices with isolated input output The connector pin out is such that commercially available cables and adapters are normally usable without modifica...

Page 18: ...oltage appearing between this reference ground and the host PC USB ground is common mode and must not exceed the isolation voltage Connector Shell is not connected To maintain shield integrity a metal connector hood should be used which must be connected to the cable screen at the remote device 3 4 Choice of Cable As speeds and distances of communication increase the choice of cable over which the...

Page 19: ...rs across the isolation barrier and not in series with the signal as would be the case if direct connection was employed The two ends of a link would normally have their grounds connected together through the signal ground line the protective ground line and or the cable shield Such a connection has an impedance such that an interfering signal caused by a difference in ground potentials is likely ...

Page 20: ...d to support the common functions of RS232 and IBM and other manufacturers frequently adopt a 9 way D type connector that provides all the necessary functionality Where this 9 way system is used manufacturers conform to interface standard EIA 574 with the pin out configuration as shown in Figure 3 2 The RS422 interface is defined in the EIA TIA standard RS422 B Electrical Characteristics of Balanc...

Page 21: ...Baud with decreasing cable length maxima at the higher rates At a signalling rate of 1 5 Mbaud by the USB485Ui the maximum cable length is specified as 80 m 260 ft see section 4 2 3 5 4 2 2 3 RS232 Cable Adapters With the variety of available interpretations of the RS232 interface it is often necessary to employ adapters or make up suitable cables to ensure that the proper connections are made The...

Page 22: ...Gnd 250 mA to Vcc Receiver Input Resistance 3 kΩ to 7 kΩ 4 kΩ 12 kΩ Receiver Sensitivity 3 V 200 mV 200 mV Receiver Hysteresis 1 15 V 50 mV 50 mV Figure 4 1 Communications Standards Summary 4 2 3 2 RS422 485 Signalling Sense The RS422 and RS485 standards define the polarity of the signalling lines as follows The signaling sense of the voltages appearing across the interconnecting cable is defined ...

Page 23: ... direction Figure 4 3 RS485 Connected in Multi Drop Half Duplex Mode 4 2 3 4 RS422 485 Bus Termination For proper operation of the RS422 485 bus in full or half duplex multi drop or point to point communication it is recommended that termination be applied to the receiver end of the data and control lines The simplest form of termination is line to line with typically a 120 Ω across the differenti...

Page 24: ...ansmission line and appropriate techniques should be used for installation of the cables In a multi drop environment the cable should be looped through each device or if a spur is necessary the spur length should be kept to a minimum If screened cable is used some thought must be given to the connection of the screen shield This screen should not normally be used as a ground return for non isolate...

Page 25: ...n the serial communication side of the interface and the following areas should be investigated Communication circuits For a communications circuit to operate correctly both ends of the circuit and the interconnecting cables must be serviceable and the correct connections made The vagaries of RS232 implementation often cause problems in making the proper connections and the manufacturers instructi...

Page 26: ...S422 485 loop back testing The connections to be made are summarised in the following table No connection needs to be made to the ground pin Signal Function 9 way Amplicon From To Pin Pin Tx A Rx A 4 8 Tx B Rx B 5 9 Figure 4 5 RS422 485 Loop Back Test Connections Loop back testing is only appropriate to full duplex operation of the RS422 485 ports See Figure 2 1 for jumper settings 4 3 3 Loop back...

Page 27: ...g Then click OK Modify the port settings to your requirement if required then click OK This will bring you to the main window and flashing cursor Now key presses will be echoed to the screen when the device and the loop back connection is correctly made For Linux a standard terminal application like minicom can be used instead of Hyper Terminal ...

Page 28: ... this device supervises all transmissions by communicating with each of the Slaves in turn and offering it a transmission slot In token ring operation each device knows its ID neighbour and only talks directly to this next device Thus communication only occurs between adjacent pairs of devices and this makes for a flexible network but can be a more difficult method to implement In half duplex mode...

Page 29: ... are three interfaces available in the range USB232U Communications RS232 I O Connector 9 way male D type with fixing screws USB485Ui Communications Isolated RS485 I O Connector 9 way male D type with fixing screws A 1 1 USB A 1 1 1 Series B connector 4 way series B connector Pinout to USB 1 1 input output standard The connector shell is connected to the USB chassis ground ...

Page 30: ... USB232U port is configured as Data Terminal Equipment DTE A 1 2 2 Data Rate The port is capable of error free transmission at data rates up to 1 M Baud A 1 2 3 I O Protection Driver outputs and receiver inputs can be shorted beyond the RS232 fault limits to 30 V without damage A 1 2 4 ESD Protection The RS232 line input outputs have on chip protection from ESD transients up to 8 kV for human body...

Page 31: ...e if the die temperature exceeds the limits A 1 3 5 I O Isolation For the isolated versions each RS485 interface is electrically isolated with no common connections to the other port Signal isolation is by opto couplers on the data lines and power to the drivers receivers is supplied through an isolated DC DC converter The design is such that it will sustain common mode voltages up to 75Vdc which ...

Page 32: ...2 Data Bits Programmable 5 6 7 or 8 A 1 4 3 Stop Bits Programmable 1 or 2 A 1 4 4 Parity Programmable Even Odd or None A 1 5 PC INTERFACE A 1 5 1 Compatibility USB Bus revision 1 1 compatible A 1 5 2 Host resources Fully plug and play configurable A 1 5 3 USB Frame Rate 1 millisecond A 1 5 4 USB packet size 64 bytes A 2 SOFTWARE The distribution software is supplied on a CD ROM Windows 98 2000 and...

Page 33: ...s Length 87 mm plus edge connectors Width 43 mm Height 26 mm A 3 1 2 Temperature Range Operating 0 C to 50 C Storage 20 to 60 C A 3 1 3 Power Requirements 5 VDC from USB Current required is less than one load unit 100 mA A 3 1 4 Dissipation Each device will dissipate less than 0 5 watts of heat ...

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