Manufacturers of Custom and Standard Industrial Embedded Single-Board Computers




Rohs compliant single-board computerRoHS compliant



General Description

The RPC-320's combination of analog, digital, memory, operator  interface, and high speed counters exceeds many system requirements. Interface to opto racks, sensors, keypads, character displays, scales, and quadrature encoders.  Network using the RS-485 port.  Its low 5 mW stand-by power consumption makes it ideal for portable or remote battery operated applications.  512K bytes of RAM can be battery backed to log data.

The RPC-320 includes a BASIC on card.  No development software is needed.  Programming in C is accomplished using the RP-10 programming card and a compiler.  Both languages support analog and digital I/O, operator interface, serial communication, and extra memory.


Function Description
Programmable Analog Inputs
Eight channels are programmable for mode and input voltage ranges.  Each channel's input mode is configurable as single-ended, or adjacent channels can be differential.  Input ranges are programmable as either 0-5V or +/-2.5V.  Resolution is 12 bits in any mode or range. 
Conversion time is approximately 1mS using the "AIN" function in RPBASIC.  Inputs are over-voltage protected to 16V.  Impedance is 100K ohms within the input voltage range.  All lines are routed to a terminal strip on the card for easy hookup.
Two amplifiers allow you to signal condition a variety of inputs.  You can amplify, filter, or buffer two signals.

Digital I/O Lines
33 digital I/O lines interface with 0-5V switch and sensor inputs, provide logic level outputs, or drive opto racks.  Each line is addressed individually or in groups of eight using the "LINE" and "LINEB" commands in RPBASIC. 

Eight lines connect to a terminal strip on the RPC-320.  A CMA-26 cable connects another 24 digital lines to a MPS series opto rack or STB-26 terminal board.  Eight of these 24 lines can drive relays, lamps, and other loads rated to 50V at 250 mA.

The last line switches a 2A load through a power FET.  It is intended to control back light power for the LCD display, but can be used for other purposes.  The multitasker in RPBASIC scans digital lines
every 5 mS and generates an interrupt on a line change or number of counts.  It is accessed through a two position screw terminal.

Opto Modules
When high power loads and inputs are required (up to 3 Amps and 260V AC or DC), the RPC-320 interfaces with the MPS series opto-isolator racking using G4 or G5 series modules.  These modules provide a minimum of 4,000V of isolation between the system and the card. 

Keypad and Display Operator Interface
LCD character displays connect directly to the RPC-320 card.  The "DISPLAY" command writes characters to the display.  Up to 320 characters and 160 x 128 pixels are displayed using the LCD 320.  Lower cost 4 x 20 and 4 x 40 character displays are also supported.  Backlighting can be switched on or off under software control to conserve power. 

The operator can input data through a 16 position KP-3 keypad. RPBASIC does all scanning, debouncing, and buffering.  The "KEYPAD" function returns a keypress position.  Up to 24 keys can be read.

Watchdog Timer
A watchdog timer resets the CPU unless it is triggered in software.  This is a safety feature should the program become stuck in an infinite loop or otherwise "crash."

Buffered Serial Ports
Two RS-232 serial ports interface with modems, displays, scales, printers, terminals and other serial devices.  One of these ports is configurable for RS-422/485 multidrop networking.  Input characters are automatically buffered by RPBASIC while a program is running  so none are missed.  Output characters are transmitted while the program continues, effectively increasing program speed. 

+5V is available at the connectors to power hand-held terminals.

Datalogging Memory
The RPC-320 comes with 32K bytes of memory standard.  About 1K is used by RPBASIC.  128K or 512K RAM can be installed for data logging.  Strings and numbers are saved and retrieved using "PEEK" and "POKE" statements.  RAM is battery backed using the DS1216DM module.

Low Power
There are three power operating modes.Default is full operating, which consumes about 100 mA with no inputs or outputs connected. A second mode reduces card current to about 20 mA. In this mode the processor is inactive. Only an interrupt, serial input, or reset will wake up the card. The analog output (D/A) is maintained and any voltage can be applied to the analog inputs. The third mode is the lowest power. The processor is inactive. Current consumption in this mode is approximately 2 mA.

Fast and Easy Programming Setup
There are no programs to install.  RPBASIC is built into the board. 

Simply run a terminal program (such as Windows Terminal, Hyperterm(r), Procomm(r), ect).  Windows Terminal and Hyper Terminal are included with Windows.

Set the baud rate and port and your PC is set up.  Connect a cable from the card to the PC.  Apply power to the board.  You will get a sign on message like the one shown below.

Picture of the setup screen for a Single-Board Computer

You can begin to program immediately.  Run the sample programs supplied with the card.  Begin scanning a keypad, opto module, control a motor,  read a voltage, or do calculations as desired right away.  In less than 5 minutes you can begin programming.

Large Program Capacity
You can use two flash EPROM sizes with the RPC-320; 32K is standard.  It stores approximately 800 lines of  BASIC code.  512K byte flash EPROM is available.  Maximum program running size at any one time is about 60K, or about 1500 lines of code, using 128K or larger RAM.

Additional programs can be loaded to replace an existing one during run time.  Using a 512K byte flash, approximately 12,000 lines (or 200 pages) of code can be stored. 

EPROMs can also store program constants, text messages, recipes, etc.  This information can be read by the BASIC during run time.  RPBASIC has two commands to facilitate data transfer.   "BSAVE" transfers binary information from RAM and saves it to EPROM.  "BLOAD" loads binary information from EPROM and transfers it to RAM.

32K of code is saved to on card flash.  64K can be installed using an external programmer.

On-Card EPROM Programmer
RPBASIC's  "SAVE" command stores your program in nonvolatile EPROM for autorun on power-up.  Up to eight programs can be saved using a 512K byte EPROM.  Erasing is done electrically and does not require a UV erasure or a 12V programming supply.

The EPROM has an internal locking mechanism to prevent accidental writing.  Thus, programs are protected against random modification.

Autorun on Power-Up
On power-up and reset, RPBASIC checks the autorun jumper.  If set, the system will load the first program into RAM and run it.

External Interrupt is Optically Isolated
RPBASIC supports an external or internal interrupt using the "ON INT" command.  An external interrupt is fed into an opto coupler or a nonisolated TTL input.  This interrupt is used to "wake up" the system in low power stand-by mode.  This line can also be used as an isolated input.

24 Bit Multimode Counter
The multimode counter is programmable to read a quadrature output or a 20 MHz signal input.  It can be programmed to interrupt when a specific count is reached.  RPBASIC reads and writes to the counter using the "COUNT" and "LINEB" commands.  The LSI 7166 multimode chip is programmable as an up/down, binary, BCD, divide-by-n, or a X1, X2, or X4 quadrature counter.

Inputs include 'A' and 'B' quadrature, load, reset, enable, and count.  Functions are programmable in software.  The counter can interrupt the processor when counting produces a borrow or carry.  An external circuit is necessary to interrupt in quadrature mode.

Real Time Clock
An optional DS1251Y calendar/clock module(order # 2084) is supported via "DATE" and "TIME" commands.  Time stamp data, set control schedules, etc.  The 24 hour clock has a resolution of 0.01 seconds.  The  calendar/clock lithium battery keeps time and backs up RAM for five years or longer. 

Technical Information

80C320  (8031 compatible, from Dallas Semiconductor), operating at 22.11184 MHz.

RPBASIC is in a 32K ROM.  Address 7000H to 7FFFH is available for custom programs.  Space from 7000H to FFFFH available if 27C512 EPROM used. 

Program and data is 32K RAM standard, 128K and 512K optional.  Battery backup is DS1251Y (order #2804). 

RAM, flash, and other I/O occupy data space on 8051.  A bank switching scheme accesses devices.

Digital I/O:
The RPC-320 has 33 digital I/O lines divided into 3 groups; 8 are from screw terminals, 24 are from a 26 pin connector at J1, and 1 is high current output only from a screw terminal.  Specifications below are for digital lines except high current.  Digital I/O are TTL compatible.  An 82C55 is used. 

Drive current 2.5 mA min. per line, sink or source. 

Output Voltage:
Low:    0.45V max. at 2.5 mA, 1V max. at 15 mA for opto rack.
High:    2.4V min., sink or source at 2.5 mA.

High Current Output:
8 of the 24 lines sink up to 500 mA at 50V.  When all 8 lines are ON, max. is 80 mA/line.  Output is disabled by substituting a dip shunt jumper for the driver IC.  This allows lines to be used as inputs. 

One line switches from 2 amperes to ground through a 'zero' ohm FET.

Keypad Input:
10 lines accept a 16-24 position matrix keypad.  Scanning, debounce, and 8 key buffering performed in RPBASIC.

Display Port:
Digital and power lines used to control LCD character displays.  Displays supported in RPBASIC. 

Serial Ports:
Two RS-232D serial ports.  All have RxD, TxD, and control lines.  COM 1 configurable for RS-232 or RS-422/485.  Termination network for RS-485 available.  Baud rates programmable from 300 to 38.4K.  Data fixed at 8 bits, no parity, 1 stop.

Watchdog Timer, Reset:
Watchdog timer resets card for 100 mS min. when enabled.  Time between resets programmable for 0.4 or 2.5 seconds. 

Analog Input:
Resolution:     12 Bits
Accuracy:       11 Bits (+/- 2 counts)
Range:            0-5V, +/- 2.5V
Input imped:   100K
Modes:            Single-ended or differential
Overvoltage:   +/-12V min.

Overvoltage reduced in IDLE 2 mode. 

Multimode Counter:
Range:          24 bits
Max. freq:    20 MHz
Inputs:          Quadrature X1, X2, or X4, single ended.  TTL level compatible
Type:            LSI/CSI LS7166
Interrupts:     Carry or borrow.  External circuit needed to interrupt in quadrature mode.

Power Requirements:
+5V, +/-5% at 100 mA max. operating.  RS-232 voltages generated on card.  IDLE 1 mode reduces card current to 20 mA max.  Tick timer and serial ports are active.  IDLE 2 mode reduces card current to 1 mA.  Currents are no-load.

Operating Temperature Range
-20C to +70C

Size: 4.6" X 7.0"
Mounting: 0.125" holes, 0.25" from edges

#1084 BASIC-52 software manual
 #2804 DS1251Y battery backup calendar/clock and RAM module
 #1041 VTC-9F serial cable


Ordering Information:




RPC-320 with 128K RAM, 512K Flash EPROM, Basic 52, and hardware manual. 


RPC-320 with 512K RAM, 512K Flash EPROM, Basic 52, and hardware manual



VTC-9F Serial cable, connects between board and PC.


CMA-26 Ribbon cable.  2 Ft. long, 26 line ribbon cable.  Connects between STB-26 and board.


STB-26 Terminal Board.  Provides a convenient way of attaching external wires to the board.  Use in conjunction with #1031 ribbon cable.


4 Line by 20 character display with cable and LED backlight.


4 Line by 40 character display with cable and LED backlight.


KP-3 keypad with cable and set of interchangeable keys.


Basic 52 Software manual. Download Here for Free