B&B Electronics RS-232 Digital Relay I/O 232DRIO User manual

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RS-232 Digital Relay I/O
Model 232DRIO
Documentation Number 232DRIO1005
pn#4520-r2
This product
Designed and Manufactured
In Ottawa, Illinois
USA
of domestic and imported parts by
B&B Electronics Mfg. Co. Inc.
707 Dayton Road -- P.O. Box 1040 -- Ottawa, IL 61350
PH [phone] -- FAX [phone]
Internet:
http://www.bb-elec.com
[email protected]
[email protected]
©B&B Electronics – January 2008

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Table of Contents
Chapter 1- Introduction........................................... 3
232DRIO Features ..................................................3
Packing List.............................................................2
232DRIO Specifications...........................................
3
Opto-Isolated Input................................................................3
Relay Outputs .......................................................................3
Power Supply........................................................................3
Communications ...................................................................3
Environment..........................................................................3
Size .......................................................................................3
Chapter 2 - Connections......................................... 5
I/O Connections............................................………5
Opto-isolated Input................................................................5
Relay Outputs .......................................................................5
Ground..................................................................................5
Serial Port Connections...........................................6
Power Supply Connections......................................7
Chapter 3 - Commands ........................................... 9
Syntax ...................................................................10
I/O Data Bytes.....................................................................11
Read I/O Lines Command.....................................13
Set Output Lines Command ..................................13
Chapter 4 - I/O Interfacing..................................... 15
Opto-isolated Input................................................15
Relay Outputs........................................................17
Chapter 5 - Software.............................................. 19
Programming Techniques......................................19
Opening a COM Port...........................................................19
Closing a COM Port............................................................19
QuickBasic..........................................................................20
Read I/O States Command.................................................20
Set Output States Command..............................................20
C/C++..................................................................................21
Read I/O States Command.................................................21
Set Output States Command..............................................21

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Demonstration Program ........................................22
Hard Drive Installation.........................................................22
Running Demonstration Program .......................................22
APPENDIX A..........................................................A-1
ASCII Character Codes........................................A-1
APPENDIX B..........................................................B-1
Hexadecimal/Decimal Conversions......................B-1

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Chapter 1- Introduction
232DRIO Features
The 232DRIO is a general purpose data acquistion controller that
is connected to your computer’s RS-232 serial port. The 232DRIO
offers 1 opto-isolated input and 2 relay outputs. With these features,
the controller can be used to sense external ON/OFF conditions and
to control a variety of devices.
The relay outputs are CMOS/TTL compatible. The optically
isolated AC/DC input are also CMOS/TTL compatible. For
maximum flexibility, both input and outputs are connected with
internal screw type terminal blocks. Three LEDs are provided to
monitor the status of each of these.
The 232DRIO connects to your computer’s RS-232 serial port
through a DB-9F connector. The unit communicates at a baud rate
of 9600, 8 data bits, no parity, and 1 stop bit. This unit can not be
powered through the handshake lines because of the higher current
requirement to drive the relays. However, the unit may be powered
by an external +12Vdc source brought in through the power pin, pin
#9 of the serial port. If the 232DRIO cannot be powered using the
previous method, it may be powered with +12Vdc @ 100mA through
the supplied terminal blocks. Power supply is available.

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Figure 1.1 – 232DRIO Module
Figure 1.2 – Simplified Block Diagram
Packing List
Examine the shipping carton and contents for physical damage.
The following items should be in the shipping carton:
1. 232DRIO unit
2. Software
3. This instruction manual
If any of these items are damaged or missing contact B&B
Electronics immediately.
232DRIO Specifications
Non-polarized, Optically Isolated Input
RELAY
SPDT
RELAY
SPDT
#2 N/O
#2 N/C
#2 Com
#1 N/O
#1 N/C
#1 Com
GND
+12Vdc
POWER
Microcontroller
TD
RD
+5V
RS-232
Transceiver
Serial Port
DB-9S
5-30 Vdc/Vac
Input
Opto
Isolator
R

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Number of Channels: 1
Indication Mode
Logic “0”: LED on, digital voltage input high
Logic “1”: LED off, digital voltage input low
Input Electrical Characteristic
Voltage input low: <1.5 VAC/VDC
Voltage input high: 5-30 VAC/VDC @ 1mA to 30mA
Isolation Voltage: 2500 V
Leakage Current: 10 µA max.
Relay Outputs
Number of Channels: 2 electromechanical relays
Factory Default: Both relays de-energized
Indication Mode
Logic “0”: LED off, Relays de-energized
Logic “1”: LED on, Relays energized
Relay Ratings
Contact (standard): 10A @ 120VAC
8A @ 30VDC (resistive)
Max. switching capacity: 1200VA/240W
Max. operating voltage: 250VAC/125VDC
Max. carrying current: 10A (AC), 8A (DC) – standard
Min. permissible load: 100 mA @ 5 VDC
Relay Form: Form C, single-pole double-throw
(SPDT)
Output Terminals: Normally open (N/O) or
Normallyclose(N/C)
Relay Life (mech.): 10 million operations min.
Relay Life (load dependent): 100 thousand operations min.
Operating Time: 10 msec. max. (mean:~5.1ms)
Power Supply
Input Voltage: 9-16 VDC
Input Current: 100 mA
Connections: Blue terminal block field wiring
Pin #9 (Power pin) of DB9F
Communications
Standard: RS-232 (unit is DCE)
Baud Rate: 9600
Format: 8 data bits, 1 stop bit, no parity
Environment
Operating Temperature: 0°-70°C
Operating Humidity: 0-95%, non-condensing
Storage Temperature: -20°-70°C
Size 4.60”L x 2.40"W x 1.32"H

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Chapter 2 - Connections
Do not make any connections to the 232DRIO until you have
read this chapter. Remember to power down the unit and any
other connected devices before making any kinds of connections.
Also be sure that the wires connected to the terminal blocks will
support the voltage and current requirements of your external
devices.
This chapter will cover the connections for the 232DRIO. There
are four sets of connections: opto-isolated input (optional), relay
outputs, serial port, and power supply.
I/O Connections
Connections to the I/O lines are made through the internal block
terminals. These should clearly be labeled on the board. Refer to
Table 2.1. See Chapter 5 for I/O interfacing examples.
Opto-isolated Input (black terminal blocks)
The non-polarized, opto-isolated input line is CMOS/TTL
compatible and can handle voltages from 0Vdc/Vac to +30Vdc/Vac.
Refer to the Specification for a complete detail.
Relay Outputs (blue terminal blocks)
The relay output lines have a maximum operating voltage of
+250Vac/+125Vdc and are CMOS/TTL compatible. Refer to the
Specification for a complete detail. Both relays are de-energized
at factory default settings.
Ground
Connect the ground correspondingly as marked. Do not
interchange the grounds for input and power. Otherwise, the input
will not be optically isolated. The input is non-polarized so the input
ground could be connected to either one of the black terminal while
the power ground must be connected as marked on the blue
terminal.

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Table 2.1 - 232DRIO Terminal Blocks
Blue
Pin # Function Black Pin #
Function
1 - Ground Input Power 1 Opto-Isolated Input
2 +12Vdc Input Power 2 Opto-Isolated Input
3 #2 N/C-Normally Closed Non-polarized
4 #2 N/O-Normally Opened 0-30 Vdc/Vac
5 #2 C-Common
6 #1 C-Common
7 #1 N/C-Normally Closed
8 #1 N/O-Normally Opened
Serial Port Connections
In order to communicate to the 232DRIO module it must be
connected to an RS-232 serial port. The unit is designed for a baud
rate of 9600, so the serial port must be set for this rate. A data
format of 8 data bits, 1 stop bit and no parity is used. The 232DRIO
is configured as a DCE device (See Table 2.2). If your
communications equipment is configured as a DTE device, such as
a standard IBM PC serial port, the 232DRIO should be connected
using a “straight through” DB-25 cable or a standard DB-9 to DB-25
cable adapter as shown in Table 2.3. If your communications
equipment is configured as a DCE device, such as a modem, the
232DRIO should be connected using a “null modem” cable (see
Table 2.4).
Table 2.2 – RS232 Connector Pinout
DB-9S
Pin #
Signal
Signal
Direction at
232DRIO
Notes
2 Receive Data (RD) Output Required
3 Transmit Data (TD) Input Required
5 Signal Ground (SG) ------ Required
9 Power pin Input Can be wired to
power unit

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Table 2.3 – 232DRIO To DTE Connections
232DRIO
Pin # Signal DTE DB-25 Connection DTE DB-9 Connection
2 Receive Data (RD) 3 2
3 Transmit Data (TD) 2 3
5 Signal Ground (SG) 7 5
9 Ring Indicator 22 9
Table 2.4 – 232DRIO To DCE Connections
232DRIO
Pin # Signal DCE DB-25 Connection DCE DB-9 Connection
2 Receive Data (RD) 2 3
3 Transmit Data (TD) 3 2
5 Signal Ground (SG) 7 5
9 Ring Indicator 22 9
Power Supply Connections
The power requirement is 12VDC at 100mA. Power to the
232DRIO can be wired through the RS-232 serial port pin #9 (power
pin) or by an external power supply through the blue terminal blocks.
Serial ports can not provide enough power to supply the 232DRIO’s
100 milliamp requirement.
Chapter 3 - Commands

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There are only two basic commands required to control the
232DRIO: set output lines and read I/O lines. For normal
environments, command strings are from three to four bytes in
length; the “!” character, the “0” (zero) character, one command
character, and one data byte (if required).
With serial communications in a laboratory environment, the
possibility of a communication error occurring is minimal. However,
in a harsh or an industrial environment the possibility increases. A
communication error occurs when a bit transmitted as a “1” is
received as a “0” or vice versa. If the 232DRIO receives a error in
one or more of the first three command characters (“!0X”), the unit
will not execute the command. However, if the 232DRIO receives a
communication error on a data byte (I/O byte for Read Digital
command or state byte for Set Output State command), the
command will be executed since the unit has no way of knowing that
there was an error.
To provide the 232DRIO with a way of detecting errors in the
data fields, an additional set of commands can be used. This set of
commands begins with the “#” (23h) character, instead of the “!”
(21h) character. Refer to Table 3.1. With these commands every
data byte that is transmitted or received is followed by it’s
complement. For example, to read I/O lines:
Command syntax:
#0R
Response syntax:
{DATA}{~DATA}
Where “~” is used to indicate the “complement of.” If DATA has
a reading of 1, the following would be received:
{01}{FE}
Where FEh is the complement of 1. The complement of number
“x” can be calculated in QuickBasic as follows:
comp = (NOT x) AND &HFF

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Table 3.1 – 232DRIO Commands
Function Command Response
Set Output Lines !0S{…} No response
Read I/O Lines !0R {…}
Set Output Lines #0S{…}{~…} No response
Read I/O Lines #0R {…}{~…}
Symbol: {…} represents one byte
<…> represents a numeric value
~ complement of the specified data byte
Before going into the specifics of each command, it is important
to understand that a byte has a numeric value from 0 to 255. The
byte's value can be represented in decimal (0 -255) format,
hexadecimal (00 - FF) format, binary (00000000 - 11111111) format
or as an ASCII character. The fixed bytes of each command will be
represented as ASCII characters, for example: “!0R”. Refer to
Table 3.1. However, it is important to remember that an ASCII
character has a numeric value. Example: the ASCII “0” (zero) does
not have a value of zero but has a value of 48. The decimal and
hexadecimal equivalents of some ASCII characters are shown in
Table 3.2. Some commands require an additional data byte to
complete the command. These data bytes may be represented in
any of the formats listed above. Refer to Appendix A for more ASCII
and decimal equivalents.
Table 3.2 – Equivalent Values
ASCII Decimal Hexadecimal
! 33 21h
# 35 23h
0 48 30h
R 82 52h
S 83 53h
Syntax
Command strings consists of three to five bytes depending on
commands used for normal or harsh environments. The first byte is
always the start of message byte. The start of message byte is
either the ASCII “!” character (normal) or the ASCII “#” character
(harsh). The second byte is the address byte. This byte allows
each unit to have a unique address (useful in RS-485 networks).
Since the 232DRIO uses RS-232 communications, this byte is
always the ASCII “0” character and can not be changed. The next
byte is the command character. This byte is ASCII character and

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used to specify which command will be executed by the
controller,either the “R” or “S” character. The set output command
requires one argument field (for normal environments) or two
argument fields (data and its complement for harsh environments).
This field contains the fourth and/or fifth data byte.
Command Syntax: !or # 0__ _
| | | | |
| | | | |
| | | | ~DataByte
| | | Data Byte
| | Command Byte
| AddressByte
Start of Message Byte
I/O Data Bytes
When constructing commands to manipulate output lines or
when reading the state of the I/O lines it is necessary to know how to
select and interpret the I/O data byte. The three I/O lines are
represented by one data byte.
A byte represents an eight-bit binary number (11111111),
therefore each byte can represent eight I/O lines. Each bit is
assigned a bit position and a weight (value). Refer to Table 3.3.
Table 3.3 – Bit Assignments for I/O Lines
Input →I #
Relay →R #
X X X
X
X I #1 R #2 R #1
Bit Position 7 6 5 4 3 2 1 0
Hex Weight 80 40 20 10 8 4 2 1
Decimal Weight 128 64 32 16 8 4 2 1
To set an output to a HIGH state the corresponding bit position
must be set to a "1". Conversely to set an output LOW the
corresponding bit position must be set to a "0". When reading I/O
lines, any bit set to a "0" indicates the corresponding I/O line is in
the LOW state and any bit set to a "1" indicates the corresponding
I/O line is in the HIGH state.

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Example 3.1 Set Output Lines
Data Byte Relays
Binary Decimal Hex Relay #2 Relay#1
XXXXXX00 0 0 de-energized de-energized
XXXXXX01 1 1 de-energized energized
XXXXXX10 2 2 energized de-energized
XXXXXX11 3 3 energized energized
Symbol: X don’t cares (default setting should all be “0”)
To energize the relays, the corresponding bit of the data byte must
be set high. Conversely, to de-energize the relays the
corresponding bit of the data byte must be set low.
(00000011, 3 in decimal, 3 in hex: energized both relay #1 and #2)
Example 3.2 Read I/O Lines
Data Byte Returned Status
Binary Dec Hex ASCII Input #1 Relay #2 Relay #1
00000000 0 00 NUL low de-energ. de-energ.
00000001 1 01 SOH low de-energ. energ.
00000010 2 02 STX low energ. de-energ.
00000011 3 03 ETX low energ. energ.
00000100 4 04 EOT high de-energ. de-energ.
00000101 5 05 ENQ high de-energ. energ.
00000110 6 06 ACK high energ. de-energ.
00000111 7 07 BEL high energ. energ.
Notice that the returned data byte starts at address 00000000 in
binary, 0 in dec., 0 in hex., or NUL in ASCII. From left to right (msb
to lsb), the first five bits are really XXXXX “don’t cares” but are
defaulted as “00000”. The remaining three bits represent input #1,
relay #2, and relay#1, respectively. A “1” or a HIGH represents relay
energized/input present, and a “0” or a LOW represents relay de-
energized/input absent.

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Read I/O Lines Command
The Read I/O Lines command returns one data byte (with the “!”)
and two data bytes (data and its complement with the “#”) that
reflects the state of the I/O lines. Bit 2 is Input #1, Bit 1 is Relay #2,
and finally Bit 0 corresponds to Relay #1. If a bit is a "0" then the
state of that I/O line is LOW. If a bit is a "1" then the state of that I/O
line is HIGH.
Command: !0R
Argument: none
Response: the state of input and 2 relays (shown in bold face)
ASCII Example:!0R<NUL>
Dec. Example: !0R<0>
Hex. Example: !0R<0>
Bin. Example: !0R<00000000>
Description: This indicates that the input and both relays are
“0”s or LOW.
Command: #0R
Argument: none
Response: data and its complement, state of the input and 2 relays
(shown in bold face)
ASCII Example:#0R<NUL><blank ‘FF’>
Dec. Example: #0R<0><255>
Hex. Example: #0R<00><FF>
Bin. Example: #0R<00000000><11111111>
Description: This indicates that the input and both relays are “0”s
or LOW. Note that the complement is returned
immediately following the data byte.
Set Output Lines Command
The Set Output Lines command is used to set the states of the
relay outputs. This command requires one data byte (in normal
environment with “!”) or two data bytes (in harsh environment with
“#”), data and its complement. This data byte specifies the output
state of each relay output. Bit 1 is Relay #2, and Bit 0 is Relay #1. If
a bit position is set to a "0" then the state of that output line will be
set LOW. If a bit position is set to a "1" then the state of that output
line will be set HIGH.

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Command: !0S
Argument: {…} (shown in bold face)
Response: none
ASCII Example:!0S<ETX>
Dec. Example: !0S<3>
Hex. Example: !0S<03>
Bin. Example: !0S<00000011>
Description: Relay #2 is energized (“1”), and Relay #1 is
energized (“1”).
Command: #0S
Argument: {…}{~…} (shown in bold face)
Response: none
ASCII Example:#0S<ETX><n>
Dec. Example: #0S<3><252>
Hex. Example: #0S<03><FC>
Bin. Example: #0S<00000011><11111100>
Description: Relay #2 is energized (“1”), and Relay #1 is
energized (“1”). Note that the complement is
returned immediately following the data byte.
NOTE: If any of these lines are defined as inputs the bit settings are
ignored. Since Bit 2 is defined as Input #1 the bit setting is ignored.
Two important ideas to keep in mind when sending commands
back to back or in sequence are the following:
1)If the “!0R” is sent, one character delay must follow immediately
before any other commands are sent.
2)If the “#0R” is sent, two character delay must follow immediately
before any other commands are sent.
For example: 1) “!0R_!0S1”
2) “#0R_ _ #0S1”
Otherwise, the microcontroller will miss the second “!” or “#” and not
interpret the second command at all since it is still trying to transmit
the returned data byte(s) to the user.
Chapter 4 - I/O Interfacing

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This chapter will explain "HIGH" and "LOW" states and show
some general examples of how to interface to the I/O lines. Caution
must be taken not to exceed 232DRIO specifications listed in
Chapter 1 when interfacing to external devices. Failure to stay
within these specifications could result in damage to the unit and will
void warranty.
Figure 4.1 – Board Layout
Opto-isolated Input
As stated earlier, the opto-isolated input line is CMOS/TTL
compatible and can also handle voltages from 0 to +30 Vdc or Vac.
The isolated input is used to sense a HIGH or a LOW state. This
can be accomplished via switch closures, contact closures, or a
solid state digital signal. When this input senses a voltage level
+5Vdc/Vac or above, it will be considered "LOW" and its input state
will be read as a "0" to the PIC® microcontroller. Conversely, when
an input senses a voltage level below +1.50Vdc/Vac, it will be
considered "HIGH" and its input state will be read as a "1" to the PIC
microcontroller. Correspondingly, the PIC will then evaluate the
incoming input and declare it as a “HIGH” if it is a “0” (at least +5V)
and as a “LOW” if it is a “1” (less than +1.5V).

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Figures 4.2 - 4.4 show examples of some typical input interfaces.
Figure 4.2 - Switch Input
Figure 4.3 - Solid State Input
232DRIO EXTERNAL CIRCUIT
5-30 Vdc/Vac
Opto Isolated Input
232DRIO EXTERNAL CIRCUIT
5-30 Vdc/Vac
Opto Isolated Input

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Figure 4.4 - Isolated Mechanical Input
Relay Outputs
Relay outputs are used to turn external devices on or off. Relay
outputs are CMOS/TTL compatible and can also operate between 0-
24Vdc and 0-115Vac. Outputs can be used to control solid state
output modules, CMOS and TTL logic circuits. Caution must be
taken not to exceed the power capability of the outputs. Refer to the
output specifications in Chapter 1.
Setting an output line to a "1" forces the output HIGH, and setting
an output line to a "0" forces the output LOW. Both relays are de-
energized at factory default settings.
NOTE: The relay circuits are not UL® approved for 120 Vac @ 10A
or 30 Vdc @ 8A (resistive) maximum line service in regards to
contact ratings. However, the printed circuit traces were followed
using UL standards (UL #1950) for minimum width and separation.
For the previous reason and safety concerns, we recommend a
maximum continuous rating of 8 amperes. In conclusion, the
voltage should still comply with the rated relay contact voltage of 120
Vac/30 Vdc max. but recommended @ 8A or lower.
It is the customer’s responsibility to determine the ultimate
safety and acceptability of our products. Failure to stay within
these specifications could result in damage to the unit and will
void warranty.
232DRIO EXTERNAL CIRCUIT
5-30 Vdc/Vac
Opto Isolated Input

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Figures 4.5 - 4.6 show examples of some typical output interfaces.
Figure 4.5 – Isolated Connection to External Circuit
Figure 4.6 – Isolated Connection to External Devices
EXTERNAL CIRCUIT
0-30 Vdc @ 8A max.
0-120 Vac @ 10A max.
232DRIO
+12 Vdc N/C
N/O Common
Common
EXTERNAL CIRCUIT
232DRIO
+12 Vdc N/C
N/O
Common 1K
+5 Vdc
0-30 Vdc @ 8A max.
0-120 Vac @ 10A max.