Amplicon 485HF9 Instruction Manual Download Page 23

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Model 485HF9

Page 23

5. TECHNICAL INFORMATION

5.1

Technical Specification

The technical characteristics of the Model 485HF9 Adaptor are in accordance with the following
electrical and physical specifications.

Except where otherwise noted, all specifications are typical at 25º C

5.1.1

Electrical Specification

Supply Voltage

+5.0 VDC to +13.0 VDC

from external supply via terminal strip

Supply Current

50 mA plus current drawn by output loads

100 mA fully loaded

RS-232 'High' signal input

+2.4 to +30 V

RS-232 'Low' signal input

–30 to +0.8 V

RS-232 Input Resistance

5 k

Ω

RS-232 'High' signal output

+9 V

RS-232 'Low' signal output

–9 V

RS-232 Output Resistance

300

Ω

RS-232 Connector fitted to Adaptor

9 way D type socket

RS-422/485 Input sensitivity

0.2 V

RS-422/485 Input hysteresis

70 mV

RS-422/485 Output drive

1.5 V minimum, fully loaded

RS-422/485 Output load

Ω

minimum

RS-422/485 Receiver I/P Termination

120

Ω

resistor across differential input terminals.

Can be disconnected by cutting an on-board link

RS-485 Tx enable

–30 V to +0.8 V

RS-485 Tx disable

+2.4 V to +30 V

Tx Enable Input Resistance

5 k

Ω

Data Rate

1 MBd

RS-232 Connector

9 way DB-9 female connector with screw-locks

RS-422/485 Connector

8 way pluggable screw terminal assembly

5.1.2

Physical/Environmental Specification

Module with connector

Packed

Size

67 x 43 x 20 mm

215 x180 x 80 mm

Weight

60 gm

250 gm

Temperature Range

Operating

Storage

0° C to +60° C

-20 to +70° C

Summary of Contents for 485HF9

Page 1: ...er 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 Model 485HF9 Instruction Manual Part Nº 859 864 34 Issue A4 Amplicon Liveline Limited Prepared by D Field Approv...

Page 2: ... the product s described in this Instruction Manual are manufactured by Amplicon Liveline Limited and perform in conformity with the following standards or standardisation documents Electro Magnetic Compatibility EMC EMC Directive 89 336 EEC LVD Directive 73 23 EEC CE Directive 93 68 EEC Jim Hicks I Eng MIEIE Managing Director Amplicon Liveline Limited ...

Page 3: ...6 3 2 1 Electrical Levels 17 3 2 2 9 25 Way Adaptors 17 3 3 RS 422 485 Application Notes 17 3 3 1 RS 422 485 Parameters 18 3 3 2 Cabling of RS 422 485 Bus 18 3 3 3 Multi drop Applications 19 3 3 4 Bus Termination 20 4 TESTING AND TROUBLESHOOTING 21 4 1 Basic Testing and Fault Isolation 21 4 1 1 Testing with the Application Software 21 4 1 2 Loop back Testing Using a Simple BASIC Program 21 5 TECHN...

Page 4: ...n allows up to 32 devices to be connected in a simple network on a single serial bus The transmitter has a tri state output and may be disabled to allow reception over the same wire pair The high impedance state transmitter disabled is commanded from an external control signal or from the host computer RTS line DC power for the Model 485HF9 Adaptor must be applied from an external source The DC po...

Page 5: ...ved from the bag inspect the board for any obvious signs of damage and notify Amplicon if such damage is apparent Do not apply power to a damaged board and do not plug it into the host computer Keep the protective bag for possible future use in transporting the module 2 This 485HF9 Instruction Reference manual Amplicon part number 859 864 34 Any additional accessories mating gender changers power ...

Page 6: ...r a period of 12 months from the date of shipment there will be no repair charge unless the fault has been caused by misuse For traceability when processing returned goods a Returned Materials Authorisation RMA procedure is in operation Before returning the goods please request an individual RMA number by contacting Amplicon Customer Services by telephone or fax on the above numbers Give the reaso...

Page 7: ...ace are known then enough information is given in this manual to make up a suitable adaptor connection cable 2 2 Connections to Model 485HF9 Adaptor Connections are made to the Model 485HF9 Adaptor at each end The RS 232 connections are automatically made when the Adaptor is plugged into the port and the RS 422 485 data control and power connections must be made through a pluggable 8 way screw ter...

Page 8: ...ide of the Model 485HF9 Adaptor printed circuit board The Adaptor as supplied is configured to suit the majority of applications requiring full duplex operation or half duplex with echo For convenience the plastic case is supplied in two parts and should only be clipped together when any configuration changes have been made Operational tests can be performed before the case is fitted The configura...

Page 9: ...ugh that a solder bridge can be easily made without using wire Before applying power to the Adaptor inspect the changes carefully to ensure that the solder has properly wetted the pads and that no other bridges have been made FIGURE 2 3 CONFIGURATION OPTIONS EN J2 GND J3 J1 GND VDC B A A B Transmit Enable External TXEN Transmit Enable RTS Receive Echo ON Receive Echo OFF UNLINKED COPPER PAD PAIR P...

Page 10: ... at its free end and the power supply should be connected to terminals 7 and 8 Terminal 7 is Ground or negative terminal 8 is the positive supply OBSERVE POLARITY when powering the adaptor If the polarity is incorrect the 485HF9 Adaptor will not operate but is protected against damage A wiring diagram for applying power to a single 485HF9 Adaptor is shown in figure 2 4 and the connections to multi...

Page 11: ... used in either full duplex simultaneous transmission and reception over two independent wire pairs or half duplex sequential transmission or reception over a single wire pair In full duplex operation a separate transmitter and receiver circuit is employed and in this mode the transmitter can be left in its enabled state at all times In half duplex operation the transmitter must be disabled by swi...

Page 12: ...t enable is under the control of a TTL level or RS 232 level signal applied to terminal 1 EN of the connector strip This control signal is active low and is internally pulled down when no signal is applied In full duplex or transmit only operation this control line can be left open circuit when the transmitter will be continuously enabled In externally controlled half duplex operation or any other...

Page 13: ... On Off in Half Duplex Operation The factory default configuration of link J3 causes the transmitted data can be echoed to the receiver in half duplex operation If this echo is not required the copper link must be severed and the solder bridge made across the other gap see paragraph 2 3 This change ensures that the RS 485 receiver is enabled disabled in opposite phase to the transmitter For full d...

Page 14: ...cted as an input The programmer can sometimes overcome this situation by ensuring that the communications protocol flushes the input buffer until the beginning of the message flag is found If this problem is encountered and a software solution is not viable two extra resistors can be added externally to the 485HF9 transceiver at one end of the bus so that the network is biased to about 1 volt when...

Page 15: ...onfigurations set accordingly The following software limitations should be remembered when allocating COM channels MS DOS 3 2 and below provides support for the first two serial ports only COM1 and COM2 MS DOS 3 3 and above supports COM1 COM2 COM3 and COM4 Other operating systems allow the use of more than two ports Check the instructions Most BASIC language interpreters compilers only support COM...

Page 16: ...ry functionality The Model 485HF9 Adaptor complies with this adopted pinout convention Although three versions of the Amplicon 485 Adaptor are available there may be occasions where a 9 25 pin conversion cable or adaptor such as the Amplicon PC AT Serial Port Adaptor 909 245 77 is useful Paragraph 3 2 2 gives the connection details for making up a suitable converter cable The RS 422 interface is d...

Page 17: ...ransmitter and associated receiver to about 15 m 50 ft 3 2 2 9 25 way Adaptors The wiring list in figure 3 1 shows the necessary connections to adapt a 9 way RS 232 port to a 25 way RS 232 port or vice versa Due note should be taken of the gender of the mating connector and a gender change can be incorporated in the adaptor if required FIGURE 3 1 DTE ADAPTOR 9 Way to 25 Way 3 3 RS 422 485 Applicat...

Page 18: ...mV FIGURE 3 2 STANDARD RS 232 422 485 PARAMETERS 3 3 2 Cabling of RS 422 485 Bus RS 232 data transmission rates are specified up to 20 kBd but are sometimes as high as 115 kBd The Model 485HF9 Adaptor can therefore be used up to 115 kBd and the maximum cable length of 1200 m will apply at all usable data rates RS 422 485 employs a differential method of signal transmission and each bus cable has t...

Page 19: ...ways of providing program control are the Master Slave and Token Ring methods The Master Slave method designates one device on the network as Master and 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...

Page 20: ...y required at the device receiver located at the far end of the cable If this is in half duplex operation then both ends of the bus cable are equipped with receivers transceivers so termination is necessary at both ends Although the 485HF9 Adaptor will drive loads as low as 27 Ω in general RS 485 transmitter circuits are specified as being capable of driving a minimum load resistance of 60 Ω so no...

Page 21: ...n be tested in isolation of external influences such as the signal cables other devices and the applications program by performing the following loop back test It is necessary to link the terminals as shown in figure 11 and run the 4 line BASIC program given below A copy of a BASIC interpreter such as QuickBASIC or GWBASIC will be required FIGURE 4 1 TERMINAL LINKS FOR LOOP BACK TEST The base addr...

Page 22: ...ls 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 etc the program is likely to hang Polarity of RS 422 485 differential data lines Not all suppliers use the same convention for the polarity of the differe...

Page 23: ...output 9 V RS 232 Output Resistance 300 Ω RS 232 Connector fitted to Adaptor 9 way D type socket RS 422 485 Input sensitivity 0 2 V RS 422 485 Input hysteresis 70 mV RS 422 485 Output drive 1 5 V minimum fully loaded RS 422 485 Output load 27 Ω minimum RS 422 485 Receiver I P Termination 120 Ω resistor across differential input terminals Can be disconnected by cutting an on board link RS 485 Tx en...

Page 24: ...BS415 5 2 2 International Mains Adaptor Power Supply 919 448 69 Wired in mains Provides 9 VDC at 200 mA to power one or two Model adaptor 485 Adaptors Mains operated 220 230 VAC Two wire Brown live blue neutral 1 5 m length mains input cable Two wire output cable of 2 m length Moulded power connector to be removed for screw terminal connection to 485HF9 Adaptor Wire with white stripe is positive s...

Page 25: ...Model 485HF9 Page 25 ...

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