Dot Graphic VFD Module q q q q q GU180x32D-K610A4 180 x 32 High Brightness Dot Graphic Display Single 5V DC Supply 3 ASCII Fonts ( 5 x 5, 5 x 7, 10 x 14) Asynchronous, SPI & Parallel interfaces Wide Temperature –40 to +85°C The module includes the VFD glass, VF drivers and microcontroller, character generation, interface logic and patented transformerless DC/DC converter. The interface type is selected by a pushbutton on the back of the module. Auto key scanning and general I/O is available on port PA0 – PA7. RS232/RS485 options. 2.5 1 13.95 24.0 31.0 6.58 1 1 19.7 CON4 CON3 CON2 79.05 117.0 124.0 18.25 CON1 1.6 6.4 3.5 3.5 Dimensions in mm & subject to tolerances. Mounting holes 3.5mm dia. CON3 & CON4 are not to be used in this implementation. CHARACTER SETS ELECTRICAL SPECIFICATION Parameter Sym Min Supply Voltage Vcc 4.5 Supply Current Icc Logic High Input VIH 3.0 Logic Low Input VIL -0.5 Logic High Output VOH 4.2 Logic Low Output VOL - Typ 5.0 350 - Max 5.25 Vcc 1.5 0.6 Unit V mA V V V V Condition VSS=0V Vcc=5V All dots VCC=5V VCC=5V IOH = -3mA Vcc=5V IOL = 20mA MINI FONT (PROPORTIONAL SPACING) 5x7 & 10x14 FONTS (FIXED SPACING) ENVIRONMENTAL and OPTICAL SPECIFICATION Parameter Value Display Area (XxY mm) 79.05 x 13.95 Dot Size/Pitch (XxY mm) 0.29 x 0.29/0.44 x 0.44 Luminance 1000 cd/m2 Typ Colour of Illumination Blue-Green (Filter for colours) Operating Temperature -40°C to +85°C Storage Temperature -40°C to +85°C Operating Humidity (non condensing) 10 to 90% @ 25°C SOFTWARE COMMANDS Hex Command 01-07 Run Macro 08 Backspace 09 Horizontal Tab 0A Line Feed 0B Home 0C Vertical Tab 0D Carriage Return 0E Clear End of Line 0F Test 10 + x + y Cursor Position 11 +xl+yt+xr+yb Set Area 12 +xl+yt+xr+yb Clear Area 13 +xl+yt+xr+yb Invert Area 14 +xl+yt+xr+yb Set Outline 15 +xl+yt+xr+yb Clear Outline 16 Set Pixel 17 Clear Pixel 18 + len + data Graphic Write Hex 19 1A + data 1B + macro+len+data 1B + 4D 1B + 4C/55 1B + 43 1B + 50/46 1B + 48/42 1B + 49 + data 1B + 44 + data 1B + 4F + data 1B + 52 1B + 4B 1B + F8-FF 1C / 1D / 1E 1F +xl+yl+xr+yb+data 20 - FF *1 Command Reset Write Mode - direction Set Macro Erase All Macros Lock/Unlock EEPROM Request Checksum Power On/Off Enable/Disable Hex Write Set Comms Enable I/O Port Set Port Lines Read Port Enable key scanning Brightness Select Font Graphic Area Write*1 Character Write Applies to version 3 software only. The module defaults to a 4 line of 30 character display using the 5x7 font with single pixel spacing. The cursor position auto increments after each character write. The bottom left of a character is placed at the cursor x,y. The M(odule) Busy line indicates the module is busy when high. Connect the H(ost) Busy input to the MBusy to disable handshaking. Use the button to select the configuration which is then stored in EEPROM. To send commands as hexadecimal, prefix the 2 bytes using character 60H. Example: `10`3F`01 = Position dot x=64 y=1. To send character 60H to the display, send 60H twice. Subject to change without notice. Doc Ref: 03872 Iss7 10 July 03 NORITAKE ITRON VFD MODULES CON1 Pin Async 1 5V 2 Nc 3 RXD 4 Nc 5 0V 6 Nc 7 TXD 8 /RES 9 MB 10 HB SPI 5V SCK /SS SIN 0V SOUT /IRQ /RES MB HB CON2 Pin 1 2 3 4 5 6 7 8 9 10 Signal 0V ENABLE PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 Nc = Do Not Connect Detailed specification, software commands and interface timing are available on request. CONTACT Noritake Sales Office Tel Nos Nagoya Japan: +81 (0)52-561-9867 Canada: +1-416-291-2946 Chicago USA: +1-847-439-9020 Munchen (D): +49 (0)89-3214-290 Itron UK: +44 (0)1493 601144 Rest Europe: +49 (0)61-0520-9220 www.noritake-itron.com GU180x32D-K610A4 Dot Graphic VFD Module GU180x32D-K610A4 SOFTWARE COMMANDS Instruction Data Format Macro Start 01H - 07H Description Start user defined macro 1-7. 08H 0DH Non destructive backspace. Cursor is moved left by the width of the currently select font. If the cursor is at the left end of the display, no cursor movement is made. Cursor is moved right by the width of the currently select font. If the cursor is at the end of the display, no cursor movement is made. Moves the cursor down by the height of the currently selected font. If the cursor is at the bottom of the display, no cursor movement is made. Moves the cursor horizontal position to 00H, the vertical positioning is dependent on the currently selected font, allowing for immediate character writing in the top-left corner of the display. Moves the cursor up one character row. If the cursor is at the top of the top end of the display, no cursor movement is made. Moves the cursor horizontal position to 00H. The vertical position is unchanged. 0EH Clear all characters from the current cursor position to the end of the display. 0FH Place module into self-test mode. The module will repetitively show a few test screens. The test mode will stop on the next received byte. Set the cursor position. (BUSY time depends on contents) Backspace (50ms) Horizontal Tab 09H (50ms) Line Feed 0AH (50us) Home 0BH (50us) Vertical Tab 0CH (50us) Carriage Return (50us) Clear EOL (2.5ms) Test (50ms) Cursor Position 10H + xpos + ypos (50us) Set Area (50us + 1ms [last byte]) Clear Area (50us + 1ms [last byte]) Invert Area (50us + 1ms [last byte]) Set Outline (50us + 1ms [last byte]) Clear Outline (50us + 1ms [last byte]) Set Pixel 11H + xleft + ytop + xright + ybot Fill specified area. All dots within the specified area are illuminated. Please note that the cursor position is affected with this command. 12H + xleft + ytop + xright + ybot Clear specified area. All dots within the specified area are cleared. Please note that the cursor position is affected with this command. 13H + xleft + ytop + xright + ybot Invert specified area. All dots within the specified area are inverted. Please note that the cursor position is affected with this command. 14H + xleft + ytop + xright + ybot Draw box outline. All dots within the specified outline are unchanged. Please note that the cursor position is affected with this command. 15H + xleft + ytop + xright + ybot Clear box outline. All dots within the specified outline are unchanged. Please note that the cursor position is affected with this command. 16H Illuminate a single pixel at the current cursor position. (50us) Clear Pixel 17H Clear a single pixel at the current cursor position. 18H + len + data 1BH + level Write graphical data, length len, direct to display. See write mode command (1AH) for graphic orientation and cursor movements. Resets display to power-on defaults: - Display is cleared. 5x7 font selected. Write Mode = 00H Brightness Level = 7. VFD Power = On. Bit 7 = graphic data orientation - 0 = horizontal, 1 = vertical (default = horizontal) Bit 6 = cursor movement - 0 = horizontal, 1 = vertical (default = horizontal) Bit 5 = cursor direction - 0 = forward, 1 = backwards (default = forwards) Bit 4 = underscore cursor - 0 = off, 1 = on (default = off) Bit 3 = underscore cursor - 0 = static, 1 = flash (default = static) Bit 1/0 = pen type - 00 = overwrite, 01 = AND, 02 = OR, 03 = XOR (default = overwrite) Send macro data to EEPROM. macro = 00H - 07H. Macro0 is executed at power-up only. A maximum of 480 bytes is allowed for macro data. The display may flicker whilst writing macro data. Set the display brightness. level = F8H - FFH. F8H = display off. F9H = minimum, FFH = maximum (default). 1BH + 4DH Clear all downloaded macros in EEPROM. Screen may blank momentarily while macro data is being erased. 1BH + 4CH / 55H 1BH + 4FH + data All data contained within the non-volatile EEPROM is locked (4CH), and no changes are possible until the unlock command 55H is executed. All data received is added to the checksum. This command will read the lower 8-bits of that checksum, before being cleared. Please note that the checksum is cleared when executing the test mode. 50H = Turn on VFD power supply (default). 46H = Turn off VFD power supply, display’s contents will be preserved. 48H = Enable hex receive mode, character 60H is interpreted as a hexadecimal prefix. 42H = Disable hex receive mode. Hex mode is enabled at power up. Set asynchronous communication baud rate and parity. Takes effect at power-up or hardware reset. Bit 7 = Automatic I/O send (0=off, 1=on). Bits 1&0 = baud rate (00=4800, 01=9600, 02=19200, 03=38400). Bit 2 = Parity (1=even, 0=none) (factory default = 19200 with no parity, automatic I/O send is off) Set I/O port direction. A ‘1’ indicates an input, a ‘0’ an output. All output lines are immediately set low. All input lines have their pull-ups enabled. This value is stored in EEPROM and will automatically be set at power up. Set Output lines on I/O port, a ‘1’ will set 5V on the output ports, or enable the pull-ups on the inputs. 1BH + 52H Read current I/O port status. A single byte is transmitted showing the current state of the I/O lines. 1BH + 4BH Set I/O port to key scanning. The I/O ports are continuously scanned for any key press. This mode is stored in EEPROM and will automatically be selected at power up. Select font. 1CH = proportional mini font. 1DH= fixed spaced 5x7 font. 1E = fixed spaced 10x14 font. (50us) Graphic Write (50us + 250us [each data byte]) Reset 19H (500us) Write Mode 1AH + data (50us) Set Macro 1BH + macro + len + data (50us) Brightness (50us) Erase Macros (80ms) Lock/Unlock EEPROM (50us + 10ms [last byte]) Checksum 1BH + 43H (50us) Power On/Off 1BH + 50H / 46H (50us) Hex/Binary Mode 1BH + 48H / 42H (50us) Set ASYNC comms 1BH + 49H + data (50us + 10ms[last byte]) Enable I/O Port 1BH + 44H + data (50us + 20ms[last byte]) Set Port Lines (50us) Read Port (50us) Enable Key Scanning (50us + 10ms[last byte]) Select Font 1CH / 1DH / 1EH (50us) Graphic Area Write 1FH + xl + yt + xr + yb + data (50us + 250us [each data byte]) Hex Prefix 60H + dhH + dlH (50ms + 50us command BUSY) Character Write 20H - FFH Write graphic data within defined area. See write mode command (1AH) for graphic orientation and cursor movements. Note: This command is available on software version 3 only. Press setup button to view. Write to the display module using a 2-byte hexadecimal number. dhH = high nibble, dlH = low nibble. E.g. Sending `19 will reset the display. Display character from selected font. (400us) Notes: Busy times are not inclusive of a 100us scan period, this must be taken into consideration. If the cursor is enabled, busy times will increase by a further 50us. All coordinates are absolute. The origin (00H, 00H) is the top left of the display. All data shown is in hexadecimal format. NORITAKE ITRON VFD MODULES GU180x32D-K610A4 Dot Graphic VFD Module GU180x32D-K610A4 GU180x32D-K610A4 SETUP The VFD module features two serial ports (synchronous & asynchronous) and a parallel port, all interfaces are TTL compatible. Interface selection/set-up can be made using the single push button switch on the back of the module. Pressing the switch for the first time will display the initial configuration menu. On each subsequent switch press the menu pointer will advance. The current menu item will be selected if the switch is not pressed within 2 seconds. To select the required interface, press the switch until the ‘COMMS’ item has been selected. Wait 2 seconds for the communication menu to be displayed. Press the switch until the required interface is selected. The factory default interface is SPI. Wait another 2 seconds to display the related communication settings. The current configuration is displayed first. Interface selection example. SYNCHRONOUS SERIAL COMMUNICATION With synchronous communications enabled, data can be clocked into the VFD module using the rising or falling edge of SCK. This is selectable by the push switch on the rear of the module, which also sets the data order. By default, data is clocked in on the rising edge with the most significant bit sent first. The host must provide adequate delays for the module to process the data, these busy times are specified in the software command section. Alternatively the host can monitor the MB (Module Busy) line. >125ns HOST SYSTEM GND VDD I/O I/O I/O I/O I/O I/O SIN tBUSY + 10us /SS SOUT >65ns GU180x32D-K610A4 SCK /SS MB /RES >125ns >125ns SCK (RISING) SCK (FALLING) VDD GND SIN (D7-D0) D7 D6 D0 D7 D6 D0 SIN (D0-D7) D0 D1 D7 D0 D1 D7 <10us The /SS pin can be used as an enable pin if other devices are connected to the serial line, and also allows byte synchronisation. The use of the /SS line is optional, and can be permanently pulled low if required. MB TTL Synchronous serial communication. ASYNCHRONOUS SERIAL COMMUNICATION The asynchronous communication speed and parity can be set with the push switch on the rear of the module, or with the ‘UART SETUP’ command. The default settings are 19200 baud with no parity. Again the host most provide adequate delays for the module to process the command and data. The module busy line (MB) will go high when data is currently being processed. <10us HOST SYSTEM GND VDD TXD RXD I/O I/O I/O RXD TXD HB MB /RES RXD GU180x32D-K610A4 START D0 D1 D2 D3 D4 D4 D5 D6 D7 PARITY tBUSY STOP MB TTL Asynchronous serial communication from host system to VFD module. VDD GND >2us START TXD The host busy line (HB) stops the module from sending data to the host until the line falls. The use of the HB and MB lines are optional, and can be connected together if not required. D0 D1 D2 D3 D4 D4 D5 D6 D7 PARITY STOP HB TTL Asynchronous serial communication from VFD module to host system. PARALLEL COMMUNICATION The 8 I/O lines can be configured as a slow parallel interface. Data on PA0-7 is clocked into the module with the Enable line, this can be set to either a rising or falling edge trigger by the push switch on the back of the module. The host must keep the data stable for the time period indicated in the timing diagram. The module busy line (MB) can be used in parallel communication mode. >125ns ENABLE (RISING) HOST SYSTEM GND VDD I/O PA0-7 I/O MB I/O ENABLE GU180x32D-K610A4 ENABLE (FALLING) >125ns VDD GND D0 - D7 >250ns DATA tBUSY <10us MB Parallel Communication. NORITAKE ITRON VFD MODULES GU180x32D-K610A4 Dot Graphic VFD Module GU180x32D-K610A4 RESET TIMING >50ns The module is reset when a low-level signal is applied to the /RES line. This will cause the module to clear the display, initialise the communication settings and set all power-up defaults. During this initialisation period, the user must delay any transmission to the module. /RES 30ms DATA I/O level change interrupt. KEYBOARD CONTROL All 8 I/O lines can be configured to scan a key matrix with up to 16 keys. The 1BH + 4BH command will configure the I/O lines to key scan mode. The I/O port status will indicate the row/column position of the pressed key. The ENABLE line acts as hardware scan enable input, and should be tied to ground. The following example enables the key-scanning mode and the automatic I/O send when using asynchronous communications. PA0 S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 S16 PA1 ENABLE KEY SCANNNG AUTOMATIC I/O SEND 1BH 4BH 1BH 49H 82H PA2 PA3 GU180x32D -K610A4 PA4 PA5 PA6 PA7 On each key press, the I/O port status will be sent out of the asynchronous communication port. e.g. pressing key switch 1, the module will send 03H to the host system. When using synchronous serial communication, the /IRQ line will indicate when a key has been pressed, the host should then issue a ‘Read Port’ command to determine the I/O port status. ENABLE I/O CONTROL The module contains simple Input and Output functions for the 8 I/O lines (PA0-PA7). All inputs include an optional pull-up resistor, 30K-120K in value. The outputs can source ~5mA and sink ~30mA. The following example sets up the I/O lines to control the 2 LED’s and provide a pull-up resistor for the switch. ENABLE I/O MODE P0/1 = OUT, P7 = IN 1BH 44H 80H SET I/O LINES VDD GU180x32DK610A4 ENABLE P7 PULL-UP, TURN ON LED1&2 LED1 1BH 4FH 80H LED2 PA0 PA1 With asynchronous communications enabled, the status of PA0-PA7 can be transmitted when a change in level is detected on any pin. This automatic response mode can be enabled by using the ‘UART SETUP’ command. When this mode is enabled, the VFD module can reliably check port changes every 15ms. With auto send disabled (default) a manual read command is required to determine the port status. READ PORT SW1 CLOSED SW1 OPEN 00H 80H PA7 GND SW1 RESPONSE 1BH 52H < 15ms > 1us /IRQ When using synchronous serial communications, the host can detect a level change with the /IRQ line on CON1. This allows the host to poll the port status only when needed. PA0 - PA7 I/O level change interrupt. I/O WRITE ~400ns When I/O control is used, the Enable line can be used as an active low read or write strobe. With the I/O read command, the enable line will clock before the module reads the I/O port status. With the I/O write command, the enable line will clock after the I/O lines have been set. I/O READ ~400ns ENABLE <250ns <250ns PA0 - PA7 I/O Write & Read. NORITAKE ITRON VFD MODULES GU180x32D-K610A4 Dot Graphic VFD Module GU180x32D-K610A4 DISPLAYING TEXT 0,0 The module contains 3 font sizes, a proportional mini-font, 5x7 pixel, and a 10x14 pixel font. Characters of any size can be written to any part of the display. All data sent to the module from 20H to FFH is treated as character data. Characters are positioned above the current cursor position, see Fig1. Each character written will include a one pixel space on the right side of the character. After each character is written to the display, the cursor position is automatically advanced. If the cursor position reaches the end of the display, the host must reposition to the next line. 0,7 6,7 The following example displays two text messages in the center of the display. 5x7 FONT SET CURSOR DISPLAY TEXT SET CURSOR 1DH 10H 30H 0FH ‘NORITAKE ITRON’ Cursor Positioning, example of writing 2 characters from cursor position 0,7. DISPLAY TEXT 10H 39H 17H ‘VFD MODULES’ The next example displays one line of text using the 10x14 font. 10x14 FONT SET CURSOR Displaying text in the small 5x7 font. DISPLAY TEXT 1EH 10H 39H 17H ‘180x32’ The module can display a cursor to aid character positioning and text input. The size of the cursor depends upon the currently selected font, and can be set to flash or remain static. 5x7 FONT SET CURSOR DISPLAY TEXT Displaying text in the large 10x14 font. ENABLE FLASHING CURSOR 1DH 10H 0DH 0EH ‘ENTER NAME: ’ 1AH 18H Using the cursor to aid user input. DISPLAYING GRAPHICS Graphical images can be displayed on the VFD module in either a horizontal or vertical byte orientation. After each graphical data write, the cursor is automatically advanced, depending upon the direction selected in the ‘Write Mode’ command. The most significant bit is positioned to the top (vertical data) or to the left (horizontal data). The following example displays a simple graphical image using horizontal graphic data. The write mode is first set to horizontal data format, with a vertical cursor movement. The cursor is positioned before sending the 8 byte of graphical data using the graphics command. MSB SET HORIZONTAL WRITE MODE SET CURSOR GRAPHIC WRITE LENGTH - 1CH 5CH 48H 3EH 1DH 1DH 14H 36H Graphic Image using horizontal data GRAPHIC DATA The next example displays a simple graphical image using vertical graphical data. The write mode is first set to vertical data format, with a horizontal cursor movement. The cursor is positioned, then the top 20 bytes are sent using the graphic write command. The cursor is then repositioned to send the bottom 20 graphical bytes. BYTE40 BYTE1 BYTE2 1CH 5CH 48H 3EH 1DH 1DH 14H 36H BYTE21 10H 3AH 0CH 18H 08H BYTE19 BYTE20 MSB 1AH 40H SET VERTICAL WRITE MODE SET CURSOR 1AH 80H GRAPHIC WRITE LENGTH GRAPHIC DATA Graphic Image using vertical data 10H 62H 08H 18H 14H 00H 00H 00H 00H 07H 04H C7H FEH 72H 73H 32H 3EH 3FH 1DH 00H 00H 00H 00H 00H 00H 10H 62H 10H 18H 14H 00H 3CH 42H 81H B9H C1H 42H 7CH 20H D8H FCH 3CH FCH CAH 49H B1H 89H 42H 3CH 00H The graphic area write command 1FH uses top-left and bottom-right XY co-ordinates to define an area to which graphical data bytes will be written. The orientation is set-up using the write mode command 1AH. Unused bits are masked where the screen area is not a byte multiple. NORITAKE ITRON VFD MODULES Displaying graphic images in vertical and horizontal format. GU180x32D-K610A4 Dot Graphic VFD Module GU180x32D-K610A4 AREA COMMANDS The VFD module contains commands to fill, clear and invert defined areas of the display. Also an outline command is available to draw rectangles around objects. The following example displays three options for the user to select, each option is contained within a box with a shadow effect. Drawing horizontal and vertical line using the fill area command creates the shadow effect. SET CURSOR DISPLAY OPTIONS 10H 21H 13H ‘SETUP’ 10H 4AH 13H ‘PRINT’ 10H 79H 13H ‘RUN’ Display options with simple text write. BOX OUTLINE TOP LEFT 14H 1BH 0AH 14H 45H 0AH 14H 6FH 0AH BOTTOM RIGHT 41H 14H 6BH 14H 95H 14H Boxes created using the ‘Set Outline’ command. SET AREA HORIZONTAL LINE FILL AREA VERTICAL LINE 11H 1CH 15H 11H 46H 15H 42H 15H 6CH 15H 11H 42H 0BH 11H 6CH 0BH 42H 15H 6CH 15H 11H 70H 15H 96H 15H 11H 96H 0BH 96H 15H Drop Shadows created with the ‘Set Area’ command. The next example uses the invert area command to select one of the options. INVERT AREA TOP LEFT 13H 70H 0BH BOTTOM RIGHT 94H 13H Option ‘Run’ selected with the ‘Invert Area’ command. WRITE MODES By default, display data that is overwritten will be cleared prior to displaying any new data. This display data can be maintained whilst writing by selecting the ‘OR’ mode with the ‘Write Mode’ command, this will effectively merge the old data with the new. The ‘AND’ write mode will only display written data if existing data is present on the display. The other ‘Write Mode’ is ‘XOR’ which can be useful for writing text on an inverted display. The following example uses the XOR mode to write text on a full display. WRITE MODE XOR MODE SET AREA TOP LEFT BOTTOM RIGHT 11H 00H 00H B3H 1FH 1AH 03H 10H 33H 13H ‘INVERETED TEXT’ Displaying inverted text using the ‘Write Mode’ command. This next example uses the XOR mode to display the percentage completed on a progress bar. WRITE MODE XOR MODE 1AH 03H 10H 41H 0DH ‘PROGRESS’ 14H 00H 12H B3H 1CH 11H 00H 12H 58H 1CH 10H 54H 1BH ‘50%’ Using inverting text for displaying progress level. NORITAKE ITRON VFD MODULES GU180x32D-K610A4 Dot Graphic VFD Module GU180x32D-K610A4 MACROS A string of data and commands can be sent to the module and stored in non-volatile EEPROM by using the macro feature. This string of data and commands can then be executed by using just one command. Up to 8 macros can be used at any one time, one of these is executed at power-up. This example uses the first macro (Macro 0) to display an initial message at power-up. WRITE TO MACRO-0 LENGTH 1BH 00H 24H POWER-UP MESSAGE 10H 39H 0DH ‘PLEASE WAIT’ 10H 21H 19H ‘INITIALISING SYSTEM’ Power-Up message using Macro 0. This next example saves the previous graphic icon into Macro 1, and then is used as a user-defined character. WRITE TO MACRO-1 LENGTH 1BH 01H 0CH SET CURSOR GRAPHIC DATA 1AH 40H 18H 08H 1CH 5CH 48H 3EH 1DH 1DH 14H 36H DISPLAY ICON 10H 0FH 09H 01H 10H 3EH 12H 01H SET CURSOR DISPLAY ICON 10H 9BH 08H 01H 10H 5FH 18H 01H Using Macros as user-defined characters. This example creates a display template, which can be helpful if many screens require the same look. WRITE TO MACRO-2 LENGTH AREA COMMANDS 19H 14H 02H 02H B1H 1DH 11H 00H 1BH 04H 1FH 11H AFH 1BH B3H 1FH 1BH 02H 1BH DISPLAY TEMPLATE RESET SET CURSOR 11H 00H 00H 04H 04H 11H AFH 00H B3H 04H DISPLAY MESSAGE 02H 10H 37H 13H ‘SYSTEM READY’ Using Macros as a screen template. EEPROM PROTECTION The EEPROM contains information such as macro data, asynchronous communication settings and I/O configuration. So it is important to protect this information from stray commands due to communication failures. To protect the EEPROM, the module contains a ‘EEPROM Lock’ command (1BH + 4CH). Once this command is issued, no further EEPROM updates can be made until it is unlocked (1BH + 55H). This feature is also accessible from the set up menu, using the push button switch on the rear of the module. USING THE CHECKSUM All data written to the module is added to an internal checksum. The lower 8-bits of this checksum can be read at any time from the module by the host system to confirm accurate data transfer. It is up to the user if or when this feature should be used. The checksum is cleared at power-up and after each checksum read. Example: Read checksum at power-up, or directly after it has been cleared. READ CHECKSUM CHECKSUM SENT TO HOST 1BH 43H 5EH Example: Read checksum after data has been written to the display. WRITE DATA READ CHECKSUM 19H 31H 32H 33H 1BH 43H CHECKSUM SENT TO HOST NORITAKE ITRON VFD MODULES 0DH GU180x32D-K610A4