Rockwell Automation 1785-Vx0B, D17856.5.9 PLC-5 VME VMEbus Programmable Controllers User Manual User Manual
Page 84
Chapter 6
PLC-5/VME Processor
Communications Commands
6-15
Counter Example
The first byte is the data-type field (field a), the 6-byte element contains
the data (field b). Bits in the control word are:
If you see:
It means:
15
up counter enabled
14
down counter enabled
13
counter done
12
overflow
11
underflow
Timer Example
The first two bytes are the data-type field (field a), the 10-byte element
contains the data (field b). Bits in the control word are:
If you see:
It means:
15
timer enabled
14
timer timing
13
timer done
9 & 8
time base (10 for 1
second)
01100110
Bit 76543210
00000000
10000000
a
ID = 6 for control,
Size = 6 bytes
value: up counter enabled, not done,
no overflow/underflow, preset = 256,
accumulated = 7
00000000
00000001
00000111
Control byte (LS)
Control byte (MS)
Preset (LS)
(MS)
00000000
(MS)
Accumulated (LS)
01011001
Bit 76543210
00001010
00000000
a
ID = 5 for timer,
Size in next one byte
value: Timer enabled, timing, not done,
preset = 10 sec, accumulated = 9 sec.
11000010
00001010
00000000
Size = 10 bytes per element
00001001
Accumulated (LS)
00000000
Control byte (LS)
Control byte (MS)
Preset (LS)
Accumulated (MS)
Preset (MS)
b
00000000
00000000
00000000
00000000
Reserved
Reserved
Reserved
Reserved