Function of Control/Status Bits
Chapter 6
623
Status Word One
Bit
Function
Status*
17
Channel Active
0 = Reset
1 = The ASCII device is enabled
16
Write Data
Acknowledge
Module toggles SW1(16)=CW1(16) to tell
PC that new data was received
15
Read Data Available
Module toggles SW1(15)
≠
CW1(15) when
it detects a change in status or receives
new data from ASCII device
14
Input String Exceeds
Maximum
0 = Reset
1 = Input string >set string length in
IW2(0013)
13
ASCII Device/Link
Error
0 = Reset
1 = Module detects parity, framing or
overrun error in string from the ASCII
device
12
Initialization Error
0 = Reset
1 = Module ceases to operate
11
Not Used
Module sets it to zero
10
Data Complete
0 = Reset
1 = Module detects delimiter at end of
string that is distributed over one or
more block transfers.
07
Powerup
Initialization
0 = Reset by CW1(07)
1 = Powerup initialization is complete
06
Not used
Module sets it to zero
05
Output Buffer Full
0 = Reset when less than full
1 = Output buffer full
04
Output Buffer Empty
0 = Reset when data enters buffer
1 = Output buffer empty
03
Input Buffer full
0 = Reset by CW1(03) when input buffer is
empty
1 = Input buffer is full
02
Input Buffer 75% Full
0 = Reset when less than 75% full
1 = Input buffer is 75% full
01
Input Buffer 50% Full
0 = Reset when less than 50% full
1 = Input buffer is 50% full
00
Input Buffer Empty
0 = Reset when data enters buffer
1 = Input buffer is empty
*The module sets these bits (unless toggled) when it detects the subject condition.
StockCheck.com