Allen-Bradley FLEX I/O 1794-ID2, User Manual, Page: 54 / 84

5–4 How Communication Takes Place and I/O Image Table Mapping with the DeviceNet Adapter
Publication 1794-6.5.15 – December 1998
Block Transfer Read Word Assignments for the Incremental
Encoder Module (1794-ID2)
(Octal Bit
⇒
) 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
Dec. Bit
⇒
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Word
⇓
Read
1 Not used PR1 PR0 S1 S0 C1 C0 G1 Z1 B1 A1 G0 Z0 B0 A0
2 Channel 0 – Stored counter value on channel 0
3 Channel 1 – Stored counter value on channel 1
4 Channel 0 – current counter value on channel 0
5 Channel 1 – current counter value on channel 1
6 Channel 0 – Counter word 0 readback
7 Channel 1 – Counter word 1 readback
8 Revision read – software version code
Where: A0 = Status of input A, channel 0 – bit = 1 when input is on
B0 = Status of input B, channel 0 – bit = 1 when input is on
Z0 = Status of input Z, channel 0 – bit = 1 when input is on
G0 = Status of input G, channel 0 – bit = 1 when input is on
G1 = Status of input G, channel 1 – bit = 1 when input is on
A1 = Status of input A, channel 1 – bit = 1 when input is on
B1 = Status of input B, channel 1 – bit = 1 when input is on
Z1 = Status of input Z, channel 1 – bit = 1 when input is on
C0 = Cal 0 – when bit is set, counter 0 has been calibrated (reset by CalReset)
C1 = Cal 1 – when bit is set, counter 1 has been calibrated (reset by CalReset)
S0 = Stored 0 – when bit is set, counter 0 value has been saved in Store 0 (reset by StoreReset)
S1 = Stored 1 – when bit is set, counter 1 value has been saved in Store 1 (reset by StoreReset)
Once a Store occurs, L0 and L1 are on until cleared by StoreReset (counter word bit 14)
PR0 = Preset 0 reached – when bit is set, counter 0 has reached value of preset
(reset by PresetReset)
PR1 = Preset 1 reached – when bit is set, counter 1 has reached value of preset
(reset by PresetReset)
Block Transfer Write Word Assignments for the Incremental
Encoder Module (1794-ID2)
(Octal Bit)
⇒
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
Dec. Bit
⇒
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Word
⇓
Write
1 Channel 0 Control Word – control word for setting the function of counter 0
2 Channel 1 Control Word – control word for setting the function of counter 1
3 Channel 0 Preset – value to load or compare with counter 0
4 Channel 1 Preset – value to load or compare with counter 1
5–7 Not used