DTL-IFB-485

DTL-IFB-485 MURATA | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 14

Technical content

Features

• Simplifies interfacing to DATEL's DTL2A, DTL2A-LC, DTL3A & DTL4A, 100W serial-input electronic loads
• Connects to PC's serial port using RS485 adapter card
• Simplifies burn-in rack and load bank connections• Microcontroller with a four-wire RS-485 interface
• Update loads individually or simultaneously
• Red/Green LEDs for fault/unit enabled
• WinBurn™ ActiveX Controls General Description The DTL-IFB-485 uses a microcontroller with a 4-wire RS-485 interface to facilitate programming the DTL2A/2A-LC/3A/4A serial-input (isolated) loads using simple ASCII command strings through the serial port of a PC. THE DTL-IFB-485 plugs in to a DTL2/3/4 load and provides an address for the load (range 0 to 255) set by two rotary hexadecimal switches on the DTL-IFB-485. The standard RS-485 specification provides for up to 32 devices connected up to 4,000 feet of cable length. The DTL-IFB-485 operates at either 9600 or 1200 baud. The DTL-IFB-485 uses special high-input impedance receivers, allowing 256 devices to be driven by a single RS-485 port. A driver card can be installed in a PC, just as a COM port (RS-232) would be and is programmed identically to a normal RS-232 port. RS-232/RS485 interface adapters can also be used. The DTL-IFB-485 provides a convenient way to manage up to 256 electronic loads dispersed over a large area, such as might be typically encountered in a burn-in system or battery load/life test system. The DTL-IFB-485 provides a 12-bit A/D option that can read back the load voltage.

Ordering Information

DTL-IFB-485 RS-485 serial Interface Board with A/D for serial-input electronic loads. WinBurn™ Active X Control available upon request (DTLx485) DTL-DB10-6 6' Cable from RS-485 port to DTL-IFB-485 Preliminary Data Sheet Figure 1. Simplified Schematic

Interface Board for Serial-Input Electronic Loads DTL-IFB-485 Mechanical Specifications I/O Connections: P1 Pin Function 1 +5 Volts Supply 2 +5 Volts Supply 3 +5 Volts Supply

4 RS485 Receive "A1"

5 RS485 Receive "B1"

6 Digital Ground

7 RS485 T ransmit "B2"

8 RS485 T ransmit "A2"

9 Digital Ground

10 Digital Ground

I/O Connections: P3 Pin Function 1 +5 Volts Supply

2 Digital Ground

3 A/D Hi Input

4 A/D Lo Input

5 Load -

6 Load -

7 Load +

8 Load +

Note: (1) dimensions in inches (mm) (2) Mounting Holes 0.125 (3.16) diameter are on 1.640 (41.48) centers

DTL-IFB-485InterfaceBoard for Serial-Input Electronic Loads Digital Input Min. Typ. Max. Units Digital Inputs (pins 4 and 5 of Connector P1): VIL 0.8 Volts VIH 2.0 Volts IIL -0.8 mA IIH 1m A Digital Outputs Min. Typ. Max. Units Digital Inputs (pins 4 and 5 of Connector P1): VIL 0.4 Volts VIH 2.4 Volts IIL -4 mA IIH 4m A Analog Input Input Voltage Range 4.096, 8.192, 40.96 Volts (See A/D Setup Section) Resolution 12 bits 4.096V 1 mV 8.192V 2 mV 40.96V 10 mV Differential Linearity Error ±3/4 LSB Integral Linearity Error ±2 LSB Accuracy (not calibrated) ±1 % FSR Accuracy (calibrated) ±0.1 % FSR Offset Error (not calibrated,) ±3/4 ±3 % FSR Offset Error (calibrated) % FSR Gain Error (not calibrated) ±2 ±8 LSB Gain Error (calibrated) % FSR Power +5 Volts Supply (pin 1, 2, 3 of P1) Current (pin1,2, 3 without DTLXA Load +100 mA Environmental Operating Ambient Temp- erature Ta, where no de- rating required. Natural Convection, vertical mount Storage Temperature –40 +105 °C Humidity (Non-condensing) 95 % Altitude Above Sea Level 10,000 feet Timing Min. Typ. Max. Units Issue command/recieve response: 3 0 msec Absolute Maximum Ratings These are stress ratings. Exposure of devices to any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those listed in the Performance/Functional Specifications Table is not implied. Power Supply Voltage (pin3): 5.5 Volts Digital Input Voltage (pins 4,5,6,7): 5.5 Volts Output Reverse-Polarity Protection: No protection Output Overvoltage Protection: No protection Storage Temperature –40 to +105°C Lead Temperature (soldering, 10 sec.) +300°C Physical Dimensions 2" x 3" x 0.675" (50.8 x 76.2 x 17.2mm) Socket extension below board 0.120 inches Pin Material Brass, solder coated Isolation, ± Load to IGround 500 Volts Isolation, any pin to either grnd 500 Volts Isolation, resistance 100 Mohm Mounting Four PCB-through-holes #4-40 clearance Weight _ _ _ ounces (_ _ grams)

T urn on the 5V power to the DTL-IFB-485’s and interface adapter if used. T o test things out, a standard dumb terminal program such as Windows Hyperterminal (step- through example starts on page 8 herein) can conveniently be used. Command Syntax The command syntac of the DL T -IFB-485 is very specific and must be adhered to for satisfactory operation. The microcontroller on board the DTL-IFB-485 has limited resources available for "command parsing", so its up to the user to provide properly structured command strings. All commands are case insensitive (i.e. A000_?R is the same as a000_?r). All commands must be followed by a carriage return (ASCII code 13) to execute. The delimiter character (underscore character_) is critical between address and data or command. A1232345L (with no delimiter) will not execute and will produce an Error response because the data is in the wrong position in the string (it looks like 345L), whereas A123--2345L (with 2 delimiters) will produce an Error response as the parser is expecting a number in the 6th character position. The delimiter character can be any with the exception of carriage return (ASCII13) or backspace (ASCII 11?). Convenient delimiter characters that the parser ignores are typically underscore_, #, x (any letter, number or symbol on the keyboard) or Space. The parser has no capability of throwing away leading spaces, zeros, etc. Any command that includes an address i.e. is unit specific, will generate a response, typically OK, FAUL T or ERROR but certain global commands such as C (clear), L (load) or G_1234 (global data load) that affect all DTL-IFB-485’s on the cable will not generate any response although they will light the activity LED’s of all units. The family of commands and responses is as follows: 1. A123_3456 Writes decimal data 3456 to load with address 123. Stores data, but does not load the output register. Unit responds with OK, FAUL T or ERROR. OK if operation is successful, FAUL T if load is out of compliance (e.g. zero voltage applied) or ERROR if error in data (non-numeric or > 4095). No response if address is invalid (no module) or out of range >255. If address only is sent i.e. Axxx, a unit with the selected address will respond with OK (this is a way to find if units are correctly connected to system and responding). 2. A123_3456L Writes decimal data 3456 to load with address 123 and loads DTL2A Series output register updating output current. Error response as in #1. 3. A234_?S Returns fault status from #234. Responds OK or FAUL T. FAUL T condition corresponds to out of compliance or no voltage at output terminals of the load. 4. A006_?V Returns A/D input channel voltage in 5 digit decimal string, range from 0.000 to 4.095/8.190/40.95V (depending on selected range). 5. A017_?R Returns range selected on A/D in single digit string. For example, responds 4.095 CAL if range calibrated or 4.095 UNC if range is uncalibrated (may be +/-3% error). Range is selected by dip switches on DTL-IFB-485 board (4.095V or 8.190V or 40.95V) 6. A123_?D Returns the value of the last data sent to the DTL2A Series load (e.g. 2037). Note that if you send A123_1234 without an L at the end to load the data, the ?D command will return the last data actually transferred to the load, not 1234. 7. L Simultaneously loads all modules with previously stored data. There is no return response to this global command. 8. C Simultaneously zeroes output of all modules. There is no return response to this global command. 9. G_0000 Loads all units with same data, regardless of address. There is no response to this command. Command will not execute if data > 4095. 10. A123_CAL Performs calibration (T est/setup purposes only). Select desired range on dipswitches on DTL-IFB-485 board. Connect a voltage calibrator to load outputs and using a dumb terminal or terminal emulation program enter the command and follow prompts. On completion, the range will be calibrated and the calibration constants (zero & gain) will be permanently stored in internal EEPROM. This command must be performed for each range separately to calibrate all ranges. All command strings must end with a Carriage Return (CR = 13 decimal) to activate the command. RS485 Communication (Cont'd) Initial Set Up If you are using a RS232 - RS485 adapter on a standard COM port, connect the transmit A (or -) terminal to line 4 of the flat cable, transmit B (or +) to line 5, receive A (or -) to line 8, receive B (or +) to line 7 and ground to line 6, 9 or 10. If you wish to connect the 5v power through the cable, connect the +5V to lines 1,2 & 3 and the common to lines 6, 9 & 10. Each DTL-IFB-485 has two hexadecimal rotary dip switches that set the unit address. Each interface board must be set to a unique address, no two or more units on the same cable can have the same address otherwise data collisions will occur on the RS-485 receive bus. This will not cause any physical damage but will result in garbled data. Select any address(es) that is (are) convenient. Example: A123 is equal to 7B in Hex so rotary switch SW2 is set to "7" and SW3 is set to "B". Set the baud rate dipswitches to 9,600 baud (as described in the previous section). If you wish to use a lower baud rate, then make changes in the terminal software settings (below) to match your selected speed. DTL-IFB-485InterfaceBoard for Serial-Input Electronic Loads

Command Syntax (Con'td) When operating from terminal emulation software, you can type in BACKSP ACE to edit out any unwanted or erroneous characters before pressing ENTER. There is a typically a delay of a few tens of milliseconds after issuing a command and receiving the response. When operating from a program, allowance should be made for the fact that responses are not instantaneous. Typical Program Sequences In typical burn in or test set up configurations, there will be multiple loads and units under test connected to the RS-485 cable. The C (clear) command provides a way of setting every load to zero either initially or for shutdown or an emergency. In some systems, it will be desirable to set all the loads to the same value. The G_xxxx command is the easiest way to do this. If different load settings are required for each U.U.T . then either the Axxx_yyyyL or Axxx_yyyy commands will do the job. Sending an Axxx_yyyyL command will immediately set the addressed load to the data value yyyy on execution of the command. Omitting the L (load) character at the end of the command and just sending Axxx_yyyy has the effect of pre- loading the data yyyy in the addressed load but not changing the output current value from its existing state. Sending the L (load) command will then subsequently update the load. T ypically you can pre-load all the loads with desired data and with a single L command update all the units together. The Axxx_?S command will return the status of a load. If it is operating normally, it will return OK but if the voltage applied to the load is below its compliance limit (typically 0.6V - 2.5V depending on DTLXA Series load type) then FAUL T will be returned. This is a simple way to determine if the U.U.T . has failed. Connecting the A/D channel up to the load output allows direct reading of the voltage to better than 0.1% precision using the Axxx_?V command. This way the Unit Under T est (U.U.T .) output voltages can be monitored precisely and if desired, controlling software can be configured to perform data acquisition functions. Simply sending an address e.g. Axxx followed by a carriage return will return an OK response from a unit set to that address. If the address is not present on the system, no response will be received. This provides a way of initially checking the system by polling for active units. Similarly the Axxx_?R (range) command returns data on the range setting of the A/D channel and its calibration status. Setting and calibrating the A/D Channel As supplied, the DTL-IFB-485 will have been calibrated and will not normally require recalibration for 3 months - 1 year. The DTL-IFB-485 board does not include any adjustment potentiometers, instead calibration constants for each range are stored in non-volatile EEPROM in the microcontroller. Updating these constants can be performed using the Axxx_CAL command which is most easily performed using a PC with terminal emulation software or a dumb terminal. Note that if any any other combination of switch settings is selected, you will receive a BAD RANGE response after the Axxx_CAL or Axxx_?R commands. Connect a voltage calibrator to the A/D channel inputs (note if these happen to be connected to the load output, the load is automatically set to zero during this procedure and will not load the calibrator). The calibrator should be capable of 0 - 20v output in millivolt steps. Type in the Axxx_CAL command. Y ou should receive a response: Input +0.010V and press ENTER or ESC to exit The input voltage requested will vary with the range (4.096V range shown). Pressing ESC will abandon calibration and you will receive an ERROR response. Also when you run the Axxx_?R command afterwards, you will receive a response

4.096 UNC - the UNC denoting that this range is no longer

calibrated. If the range is uncalibrated, the raw A/D data is returned and because of zero offset and gain errors, is likely to be only 1% accurate. Pressing the ENTER key will load the zero offset constant into EEPROM and proceed to the next step unless you have applied the wrong voltage. A check is made that the input voltage is within ±100% of the requested value, if not a BAD INPUT response is returned and calibration is abandoned. Assuming all is correct you will receive the next response: Input +4.000V and press ENTER or ESC to exit If the calibrator input is more than ±2.5% away from the requested value, you will receive the BAD INPUT message and calibration will be abandoned. Otherwise, you should receive the OK response and this range will then be calibrated. This can be checked with the Axxx_?R command which should respond 4.096 CAL (in this case). Using the Axxx_?V command and different calibrator settings, you can check other input voltages to your satisfaction. Note that calibration must be repeated on each range to calibrate all ranges, although this is unnecessary if you operate the DTL- IFB-485 on one fixed range. First select the desired range on the A/D channel dipswitch as shown below: DTL-IFB-485 Interface Board for Serial-Input Electronic Loads

Although most of this note describes operation with a dumb terminal, you can obviously issue commands from a program written in any language of your choice. All that is important to observe is that the command strings are correct in syntax and of the right length. For instance in BASIC: OPEN “COM1:9600” AS #1: opens COM1 port for I/O A$ = “A012_?V”: setup command string to read A/D PRINT #1, A$: send command (note PRINT adds a CR) P AUSE 20: wait 20 milliseconds INPUT #1, X$: read result into X$ Key points to note are that you must send an ASCII carriage return after the command string (character 13). The DTL-IFB-485 will not start parsing the command until it receives a carriage return or the command string is greater than 10 characters long (which should not happen in normal operation). The input buffer length of is limited to 10 characters. Commands longer than this may be executed or ignored (e.g. A123_1234LXXXXXXX will be treated as A123_1234L, but some of the additional characters may end up in the leading positions of the input buffer and mess up the next command, requiring resending of the command. InterfaceBoard for Serial-Input Electronic Loads DTL-IFB-485 Co Coding Table Unipolar Input Ranges ASCII Code Binary Equivalent Scale 0 to +4.096V 0 to +8.192V 0 to 40.96V +FS - 1 LSB +4.095V +8.190V +40.86V FFF 1111 1111 1111 7/8 FS +3.584V +7.168 +35.84V E00 1110 0000 0000 3/4 FS +3.072V +6.144V +30.72V C00 1100 0000 0000 1/2 FS +2.048V +4.096V +20.48V 800 1000 0000 0000 1/4 FS +1.024V +2.048V +10.24V 400 0100 0000 0000 1/8 FS +0.512V +1.024V +5.12V 200 0010 0000 0000 1 LSB +0.001V +0.002V +10.00V 001 0000 0000 0001 0 +0.000V +0.000V +0.000V 000 0100 0000 0000 After sending only a carriage return with line feed, the next command will be skipped and may need to be resent. Remember that any addressed (unit specific) command will produce a response. After the command has been sent, it takes a few tens of milliseconds for the DTL-IFB-485 to process it and respond. Don’t try and read back data immediately. Also in the event that there is no response, you need some form of timeout so that your program does not hang waiting for input.

Adding DTLx485 Active X Control to Your Project's Toolbox After installing the WinBurn™ DTLx485, you can add the control to your Visual Basic-based application as follows: On the menu tab, select Project, and then click on Components, which will display a Components Dialog Box (see Figure _ _). Alternatively, right-clicking on the T oolbox also brings up the Component Dialog Box. To add the DTLx485 ActiveX control to your application project, click on the Browse button, and locate the DTLx485.ocx file (WinBurn™ default directory of C:\\Program Files\\DA TEL\\DTLx\\DTLx485. Click on the DTLx485.ocx file to add it to the Components list. Now, either double-click on the DTLx485, or select the check box to the left of the DTLx485 name to add it to the T oolbox. Click OK to close the Components dialog box. DTLx485ctl Class/Members Under Visual Basic, the WinBurn™ DTLx485 ActiveX Control has the "Class" DTLx485ctl, with the following "Members" to point out: CheckFaultStatus Function: Returns the status of the DTLXA Series Fault Line 0 = No Fault 1 = Fault 2 = Time Out 3 = Port Not Open ClosePort Function: Closes the Serial Communication Port 8 = Run time error Col Property: Sets the DTLXA Series load position (Column = 0 -15 EL Type (DtlT ype?) Property: Sets the DTLXA Series Model Used (Current/ Voltage) 2 =DTL2A/DTL2A-LC 3 = DTL3A 4 = DTL4A LastReadVoltage Property: Reports the last A/D reading -1 = Error LoadStoredCurrent SubRoutine: Updates load to value set for load OpenPort Function: Opens the Serial Communication Port PortNumber Property: Returns/sets the Communication Port ReadVoltage Function: Performs A/D conversion to read voltage (presumably at load) RequestAmps Property: Prepares the load for the current value to be loaded with the StoreLoadCurrent and SetLoadCurrent commands WinBurn™ DTLx485, Port Control Developing an application that controls "instruments", whether they be test systems or burn-in racks, requires a user to first check the communication between the PC and the "instruments". The DTL-IFB can be connected to a standard PC RS232 COM port with an appropriate RS232/RS485 adapter (see Figure 4). Alternatively, a plug-in RS485 board can be plugged into the PC. COM1 and COM2 ports are typically brought out on the rear of a PC, and plug-in cards typically use COM3 or COM4. ResetAllLoads SubRoutine: Resets all loads to zero current ResetLoads SubRoutine: Resets individual load to zero current Row Property: Sets the DTLXA Series load position (Row = 0 - 15 SetAllLoadCurrents Function: Sets all DTLXA Series Load Input Latches to the same load current value. This command requires all loads to be of the same type voltage/current (i.e., all 20A/ 50V models) SetLoadCurrent Function: Sets DTLXA Series Load with load current value to be set with next "StoreLoadCurrent", after RequestAmps sets value StoreLoadCurrent Function: Updates load to value set for load In general: Default properties are: Com Port = 5 (typical for 485 board...reset to 1 or 2 if using PC's com Port. Load = 2 for a DTL2A, change if DTL3A or DTL4A Row/Column set to 1st unit (0,0), change for multiple unit systems. T o set a particular load's current, you'll first set properties if the Default settings don't apply. Then you'll do a RequestAmps, to set the desired current value. Then, a StoreLoad Current will enter this into the 1st latch. Finally, a SetLoadCurrent (or SetAll Load Currents) command, will update the loads with a new value.

examples of dimensioning the Rows and Columns in code. and/or power-cycle burn-in applications be desired. now update the load with the value entered in the text box. the DUT . User's can also poll the DTL-IFB-485's Fault line. Figure 14. OK or Open Port Invalid Message

DTL-IFB-485InterfaceBoard for Serial-Input Electronic Loads DA TEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DA TEL logo is a registered DA TEL, Inc. trademark. DA TEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 T el: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 Internet: www.datel.com Email: sales@datel.com Data Sheet Fax Back: (508) 261-2857 DA TEL (UK) LTD. Tadley, England Tel: (01256)-880444 DA TEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01 DA TEL GmbH München, Germany Tel: 89-544334-0 DA TEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025 INNOVATION and EX CELL ENCE ® ® ISO 9001ISO 9001 DS-04XX 7/03