Samson 3785 series, Mounting And Operating Instructions

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7.3 Parameter description
SP - Set point with status: Reference variable w in "Auto" operating mode
The reference variable w of the positioner is preset via SP in automatic mode ("Auto").
SP consists of a floating point value (4 bytes) and the associated status (1 byte).
Value and status must be transferred together (data consistency = 5 bytes). If the status of the
reference variable is "bad" (value < 64dec.), the positioner remains in the fail-safe position
determined by the actuator.
RCAS_IN/RCAS_OUT: Reference variable w in "RCAS" operating mode
The reference variable w of the positioner is preset in the REMOTE CASCADE "RCAS" opera-
ting mode via RCAS_IN/RCAS_OUT. RCAS_IN/RCAS_OUT both are made up of one float-
ing point value (4 bytes) and the associated status (1 byte).
Value and status must be transferred together (data consistency = 5 bytes). If the status of the
reference variable is "bad" (value < 64dec.), the positioner remains in the fail-safe position
determined by the actuator.
NOTE: The RCAS operating mode is implemented in version K1.60 and higher.
READBACK - Current position with status: Controlled variable x
The position feedback is transmitted via the READBACK parameter and consists of a floating
point value (4 bytes) and the associated status (1 byte).
POS_D - Discrete valve position feedback with status: Final position indication
The final valve position is indicated via the POS_D parameter and consists of one message
value (1 byte) and the associated status (1 byte).
The message value is encoded as follows:
0 = not initialized, 1 = closed (x< 0.5%), 2 = open (x>99.5%), 3 = intermediate
CHECKBACK - Device status: Detailed device information, coded bit-wise encoded
Bit no. Name Description Byte
0 CB_FAIL_SAFE Fail-safe position (MODE = out of service)
0
1 CB_REQ_LOC_OP Request for local operation
2 CB_LOCAL_OP Device in local mode
3 CB_OVERRIDE Emergency operation / Forced venting active
4, 5, 6 Not used
7 CB_TRAV_TIME Status of movement monitoring (is reset automatically) 0
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EB 8382-1 EN
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