Emerson E300 Series Design Manual page 237

Safety Product Mechanical
information information installation
Protocol
t + t
ST
where tcal ≤ t
Endat 2.1 encoder
t + t
D
where t
t + t
ST
where tcal ≤ t
EnDat 2.2 encoder
t + t
ST
where t
t + 3T + NtT + 5T
BISS
D
t + T + NtT
D
SSI
cannot be measured, and so a value of 1.25 μs is used)
(t
D
where:
Value
t
EnDat start time
ST
t
Transmission delay from the drive to the encoder and back
D
T 1 / baud rate
t
Position calculation time
cal
Ns Single turn bits for a rotary encoder
Nt Total number of position information bits
tm Encoder recovery time
t
Time for additional information
Add
Drive Encoder Type (C01): Any other type of device
Drive Encoder Low Speed Update Rate Active (C27) is always zero.
C28
Mode
Minimum
Default
Type
Display Format
Coding
Encoder Simulation Source (C28) is used to select a parameter as the input to the encoder simulation system. If Encoder Simulation Source (C28) is
zero then no source is selected and the encoder simulation system is disabled. The encoder simulation output connections are shared with the Drive
position feedback interface, and so encoder simulation may be disabled because the connections are not available. See Encoder Simulation Status
(C29) for details.
Any parameter can be selected as the source, but it is assumed that the input is a 16 bit value with a range from 0 to 65535 or from -32768 to 32767.
The source parameter is treated differently depending on the value of Encoder Simulation Mode (C31) as given in the table below.
Encoder Simulation
Mode (C31)
Hardware (0)
Lines Per Rev (1) or Ratio (2)
SSI (3)
Although Encoder Simulation Source (C28) is not a standard source parameter in common with other sources the actual source is only changed on
drive reset.
E300 Design Guide
Issue Number: 1
Electrical Getting
User Menu A Commissioning
installation started
Time for full position
+ 10T + 2T + NtT + 5T
D
+ t /2+ 10T
ST D
+ 2T + NtT + 5T
cal
> t + t /2 + 10T
cal ST D
+ 10T + 3T + NtT + 5T
D
+ t /2+ 10T
ST D
+ t + 3T + NtT + 5T
D cal
> t + t /2 + 10T
cal ST D
Description
Encoder Simulation Source
RFC-A, RFC-S
A.00
A.00
16 Bit User Save
Menu Param Alpha Numeric
RW, PT, BU
Encoder Simulation Source (C28) must be set to Drive Encoder Position (J53) for the output to be enabled and
the position from the Drive position feedback interface is used and Drive Encoder Position (J53) is the source.
If Encoder Simulation Source (C28) = 3.029 (i.e. Drive Encoder Position (J53) is the source) then Drive Encoder
Position (J53) and Drive Encoder Fine Position (J54) are combined as a 16 bit value with 16 bit fractional part as
the input to the encoder simulation system, which gives additional output resolution if encoder simulation ratio is
greater than unity.
The encoder simulation system is intended to be used with a 16 bit source parameter. If the source of the
encoder simulation system is not a 16 bit parameter then the drive uses the source parameter as follows.
1 bit parameter: Zero extended
8 bit parameter: Sign extended if BU attribute is zero (signed), otherwise zero extended (unsigned) 32 bit
parameter: Only the least significant word is used.
For SSI output mode the number of bits included in the output can be selected (see Encoder Simulation Mode
(C31) for details).
Advanced
Diagnostics Optimization CT MODBUS RTU Technical Data
Parameters
For 100 K baud = 5 μs, 200 K baud = 2.5 μs, for all other baud rates = 2 μs
Drive Encoder Line Delay Time (C26)
Drive Encoder Comms Baud Rate (C06)
Drive Encoder Calculation Time (C24)
Drive Encoder Comms Bits (C08) − Drive Encoder Rotary Turns Bits (C07)
Drive Encoder Comms Bits (C08)
Drive Encoder Recovery Time (C25)
t = 31T + t + 30T
Add ST
Maximum
Units
Update Rate
Decimal Places
Description
Time for complete data exchange
Time for full position + t
m
Time for full position + t + t
Add m
Time for full position + t
m
Time for full position + t
m
Source
BH.999
Reset read
3
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