LTi Drives ServoOne Single axis system Series Specification page 5

2. Use of SSI Encoder Simulation
2.1 Enabling SSI Encoder Simulation
SSI Encoder Simulation is enabled as soon as parameter TOPT_SSI_EncSimEnable
(P 2800) is set to 1. The parameter is located in the parameter group
"Encoder > SSI Encoder simulation".
2.2 Parameter description for SSI Encoder
Simulation
The parameters are in the parameter group "Encoder > SSI Encoder simulation", and all
have the prefix "TOPT_SSI".
ID Parameter Unit Access
2800 EncSimEnable r/w
2801 MultiT Bit r/w
2802 SingleT Bit r/w
2803 Polarity r/w
2804 Phase r/w
2805 ParityEnable r/w
2806 ParityType r/w
Table 2.3 SSI Encoder Simulation parameters
Data Description
type
UInt16 Enable SSI Encoder Simulation
UInt16 Number of multi-turn bits to transfer
UInt16 Number of single-turn bits to transfer
UInt16 No-load level of data line
False Clock line resting at Low level
True Clock line resting at High
level
UInt16 Indicates the clock edge at which new data
are set
False Sets data on the leading
edge
True Sets data on the following
edge
UInt16 Enable the parity bit
UInt16 ODD Odd parity
EVEN Even parity
ID Parameter Unit Access
2807 SyncOffset µs r/w Float32
2808 SyncUse r/w
2809 InSync r
2810 EncobsUse r/w
Table 2.3 SSI Encoder Simulation parameters
2.3 Notes on parameterizing the SSI resolution
The ServoOne supports transfer of a total of 32 information bits which can be broken
down in any way into single-turn and multi-turn information. When generating the
position information, parameter CON_PCON_ActPosition (P 0412), likewise presenting a
32-bit variable, is used as the data source. The 32 bits of this parameter can likewise be
broken down into multi-turn and single-turn information. It is important in parameter
setting that the SSI Encoder Simulation does not, for example, transfer more single-turn
bits than correspond to the internal resolution, as they could otherwise not be filled
with information. Parameter MPRO_FG_PosNorm (P 0270) defines this resolution. The
default setting for this parameter is 1048576, corresponding to 2^20. So with default
settings the ServoOne expects 12 multi-turn and 20 single-turn bits. In this case it would
not make sense to transfer more than 12 multi-turn bits, as the number overflow would
occur at the 12th bit, despite a higher parameter setting. Nor would it make sense to set
the number of single-turn bits higher than 20 here, as in this case the additional bits are
always filled with 0.
Specification
Data Description
type
Shift of synchronization signal to closed-loop
control cycle
UInt32 Synchronization to read cycle
UInt32 False ServoOne does not run
synchronously with the read
clock
True ServoOne has synchronized
to the read cycle
UInt32 Enables transfer of an additional encoder
monitoring bit
ServoOne
[ SSI Module
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