Chapter 6 digital and opto ports – Remote Processing RPC-30 User Manual
Page 25
CHAPTER 6
DIGITAL AND OPTO PORTS
RPC-30
Page 23
Interfacing to switches and other devices
The STB-26 terminal board provides a convenient way
of interfacing switches or other digital I/O devices.
Lines at J3 are connected to the STB-26 with a CMA-26
cable. Digital devices are then connected to the screw
terminals on the STB-26.
Switches may be connected directly to a line. When
jumper W6 configures the resistors as pull ups, a switch
closure to ground at a line is read as a 0.
When W 6 configures the input re sistors as pull downs,
one end of the switch m ust be tied to + 5 volts. If this is
not possible or convenient, a 1K resistor can be tied
between an input and + 5 volts to force it high when a
switch is open.
Configuring digital I/O lines
Lines are configured during progr am execution using the
CONF IG PIO command. On power up or reset, all lines
are inputs.
When a line is configured as an output, it can sink a
maximum of 2. 5 mA at 0. 4V and can source a minimum
of 2.5 ma at 2. 4V. W hen driving opto modules, the
outputs sink 15 mA at 1.0V.
Digital I/ O prog ramm ing exam ple
The follow ing exam ple read s a switch at po rt A, bit 3
(J3-25), reads an opto module at channel 1 and writes an
opto module at channel 5. A LE D is controlled through
the high current port at J3-10 (port B, bit 0).
200 D = BIT(0,3)
:'Read switch status, port A
210 F = OPTO(1)
:'read opto module, channel 1
220 OPTO 3,ON
:'write module, channel 3
230 BIT 1,0,1
:'turn on led at J3-10
240 BIT 1,0,0
:'turn off led at J3-10
250 A = LINE(3) :'Reads pin 3 at J3
Conne ctor pinou t - J3
Pin #
82C55
Description
Opto
Channel
19
Port A, line 0
8
21
Port A, line 1
9
23
Port A, line 2
10
25
Port A, line 3
11
24
Port A, line 4
12
22
Port A, line 5
13
20
Port A, line 6
14
18
Port A, line 7
15
10
Port B, line 0
High current
16
8
Port B, line 1
High current
17
4
Port B, line 2
High current
18
6
Port B, line 3
High current
19
1
Port B, line 4
High current
20
3
Port B, line 5
High current
21
5
Port B, line 6
High current
22
7
Port B, line 7
High current
23
13
Port C, line 0
Lower C
0
16
Port C, line 1
Lower C
1
15
Port C, line 2
Lower C
2
17
Port C, line 3
Lower C
3
14
Port C, line 4
Upper C
4
11
Port C, line 5
Upper C
5
12
Port C, line 6
Upper C
6
9
Port C, line 7
Upper C
7
26
Ground
2
+ 5V