ifm electronic RM3001 - Handbuch (Seite 50)

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3.2.5 Multi/Single separation
Multiturn encoders enable to split the 32-bit format of the position value. When the control bit is activated
for the multiturn/singleturn separation, two separate values are transferred for the singleturn and multiturn
position.
DDLM_Data_Exchange: input words
Word
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Contents
Word 1 Word 0
Multiturn position Singleturn position
3.2.6 Running indication
When the control bit for the running indication is set, the position value is stored every 500 µs and
compared with the position value one second before. This enables to monitor a continuous process by
means of the running indication. If the position value has not changed within 1 s, bit 28 is set in the input
word.
DDLM_Data_Exchange: input word bit 28
Word
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Contents x
Word 1 Word 0
position value
3.2.7 Data_Exchange Alarm
When the control bit for the Data_Exchange Alarm is set, the diagnostic bytes of the encoder can be
polled online. If bit 30 is set in the output word, the diagnostic bytes of the measuring instrument are
polled. A possibly complicated polling of the diagnostic bytes via function modules is not necessary.
DDLM_Data_Exchange: output word bit 31
Word
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Contents 1
Word 1 Word 0
3.2.8 Control bit for limit switch function
When the control bit for the limit switch function is activated, two position values can be set. When the
current position values exceed or fall below these values, this is indicated by the respective bits in the
input word. Within the two limit switch values both signalling bits are set to zero.