The Output Pin (Rts/Pin 8) - Campbell SDM-SI01A Product Manual

'CR1000 example program showing how to detect the state of the input line on an
'SDM-SIO1A using the SDMGeneric instruction
Public sio1response As Long, Inputstate As Boolean
Const addr = 0 'constant sdm address CHANGE with SDM-SIO1A address
Const cmd = 1 'constant, command 1 returns the input state in bit 16
Const bytes_out =
Const bytes_val =
Const big_endian =
Const delay_usec =
Const Values_in = 1
'Main Program
BeginProg
Scan (1,Sec,0,0) 'Or whatever scan rate is being used
'Use the SDMGeneric instruction to send command 0x01 which returns the input
'line state as bit 16
SDMGeneric(sio1response,addr,cmd,bytes_out,"",Values_in,bytes_val, _
big_endian,delay_usec)
'bit 16 set for input line high or low so check the value and set a Boolean
'var TRUE or FALSE accordingly
Inputstate = sio1response
NextScan
EndProg
The input line can accept 0 and 5V logic inputs OR –12 and +12V RS-232 level inputs. The
following table shows a breakdown of the different input voltages allowed and the state of the
input line flag.
Voltage on the input line State of bit 16
+12V
–12V
5V
0V
A.2 The output pin (RTS/pin 8)
To set the output pin (RTS/pin 8) you must use the
The spare I/O lines are RS-232 lines, NOT logic lines. This means that the output line voltage is
–12V and +12V (approximately), not 0 and 5V.
CRBasic Example 2: Detecting the state of the input line
0 'constant number of bytes out - none sent
2 'two bytes returned
1 '1=(big endian)
-0 'delay between outgoing bytes (negative means delay also
'for incoming bytes)
AND &H8000
1
0
1
0
SDM-SIO1A and SDM-SIO4A Serial Input/Output Modules
SerialOutBlock() instruction.
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