[
SSI Module
]
Specification ServoOne 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 Data
type
Description
2800 EncSimEnable r/w UInt16 Enable SSI Encoder Simulation
2801 MultiT Bit r/w UInt16 Number of multi-turn bits to transfer
2802 SingleT Bit r/w UInt16 Number of single-turn bits to transfer
2803 Polarity r/w UInt16 No-load level of data line
False Clock line resting at Low level
True Clock line resting at High
level
2804 Phase r/w 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
2805 ParityEnable r/w UInt16 Enable the parity bit
2806 ParityType r/w UInt16 ODD Odd parity
EVEN Even parity
Table 2.3 SSI Encoder Simulation parameters
ID Parameter Unit Access Data
type
Description
2807 SyncOffset µs r/w Float32 Shift of synchronization signal to closed-loop
control cycle
2808 SyncUse r/w UInt32 Synchronization to read cycle
2809 InSync r UInt32 False ServoOne does not run
synchronously with the read
clock
True ServoOne has synchronized
to the read cycle
2810 EncobsUse r/w UInt32 Enables transfer of an additional encoder
monitoring bit
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.
