Adsorption Troughs

The 8 to 12 adsorption troughs are controlled with a Process Logic Controller M251 from Schneider. This PLC reads the analog signals returned by the surface tensiometers. The temperature of the liquid interfaces are controlled with a thermostatic bath and monitored with compact pyrometers. A gas can be circulated above the interface via a flow-rate controller. In addition, the PLC controls the heating of the neutron and laser windows to prevent condensation. All these devices are controlled from the touch panel of the PLC which is also used to control the Langmuir Trough.

ModBus registers

Address	Access	Type	Description
40001	Read	Real	A1 — Surface tension signal x (V)
40003	Read	Real	A1 — Coefficient a
40005	Read	Real	A1 — Offset due to paper probe b
40007	Read	Real	A1 — Constant c for zeroing the sensor (relative measurement)
40009	Read	Real	A1 — Surface tension a x + b - c (mN/m)
40011	Read	Real	A3 — Surface tension signal x (V)
40013	Read	Real	A3 — Coefficient a
40015	Read	Real	A3 — Offset due to paper probe b
40017	Read	Real	A3 — Constant c for zeroing the sensor (relative measurement)
40019	Read	Real	A3 — Surface tension a x + b - c (mN/m)
40021	Read	Real	B1 — Surface tension signal x (V)
40023	Read	Real	B1 — Coefficient a
40025	Read	Real	B1 — Offset due to paper probe b
40027	Read	Real	B1 — Constant c for zeroing the sensor (relative measurement)
40029	Read	Real	B1 — Surface tension a x + b - c (mN/m)
40031	Read	Real	B3 — Surface tension signal x (V)
40033	Read	Real	B3 — Coefficient a
40035	Read	Real	B3 — Offset due to paper probe b
40037	Read	Real	B3 — Constant c for zeroing the sensor (relative measurement)
40039	Read	Real	B3 — Surface tension a x + b - c (mN/m)
40041	Read	Real	C1 — Surface tension signal x (V)
40043	Read	Real	C1 — Coefficient a
40045	Read	Real	C1 — Offset due to paper probe b
40047	Read	Real	C1 — Constant c for zeroing the sensor (relative measurement)
40049	Read	Real	C1 — Surface tension a x + b - c (mN/m)
40051	Read	Real	C3 — Surface tension signal x (V)
40053	Read	Real	C3 — Coefficient a
40055	Read	Real	C3 — Offset due to paper probe b
40057	Read	Real	C3 — Constant c for zeroing the sensor (relative measurement)
40059	Read	Real	C3 — Surface tension a x + b - c (mN/m)
40061	Read	Real	D1 — Surface tension signal x (V)
40063	Read	Real	D1 — Coefficient a
40065	Read	Real	D1 — Offset due to paper probe b
40067	Read	Real	D1 — Constant c for zeroing the sensor (relative measurement)
40069	Read	Real	D1 — Surface tension a x + b - c (mN/m)
40071	Read	Real	D3 — Surface tension signal x (V)
40073	Read	Real	D3 — Coefficient a
40075	Read	Real	D3 — Offset due to paper probe b
40077	Read	Real	D3 — Constant c for zeroing the sensor (relative measurement)
40079	Read	Real	D3 — Surface tension a x + b - c (mN/m)
40081	Read	Real	Temperature setpoint (°C)
40083	Read	Real	A+B — Temperature (°C)
40085	Read	Real	C+D — Temperature (°C)
40087	Read	Real	A+B — Gas flow rate (l/min)
40089	Read	Real	A+B — Gas flow rate setpoint (l/min)
40091	Read	Real	C+D — Gas flow rate (l/min)
40093	Read	Real	C+D — Gas flow rate setpoint (l/min)
40095	Read	Real	A1 — Trough surface (mm2), equal to 0 if unused
40097	Read	Real	A2 — Trough surface (mm2), equal to 0 if unused
40099	Read	Real	A3 — Trough surface (mm2), equal to 0 if unused
40101	Read	Real	B1 — Trough surface (mm2), equal to 0 if unused
40103	Read	Real	B2 — Trough surface (mm2), equal to 0 if unused
40105	Read	Real	B3 — Trough surface (mm2), equal to 0 if unused
40107	Read	Real	C1 — Trough surface (mm2), equal to 0 if unused
40109	Read	Real	C2 — Trough surface (mm2), equal to 0 if unused
40111	Read	Real	C3 — Trough surface (mm2), equal to 0 if unused
40113	Read	Real	D1 — Trough surface (mm2), equal to 0 if unused
40115	Read	Real	D2 — Trough surface (mm2), equal to 0 if unused
40117	Read	Real	D3 — Trough surface (mm2), equal to 0 if unused
40119	Read/Write	Real	NOMAD Control — Temperature setpoint (°C)
40121	Read/Write	Real	NOMAD Control — A+B Gas flow rate setpoint (l/min)
40123	Read/Write	Real	NOMAD Control — C+D Gas flow rate setpoint (l/min)
40125	Read/Write	Real	NOMAD Control — Temperature tolerance (°C)
40127	Read/Write	Real	NOMAD Control — Gas flow rate tolerance (l/min)
40129	Read/Write	Integer	NOMAD Control — Year
40131	Read/Write	Integer	NOMAD Control — Month
40133	Read/Write	Integer	NOMAD Control — Date
40135	Read/Write	Integer	NOMAD Control — Hour
40137	Read/Write	Integer	NOMAD Control — Minute
40139	Read/Write	Integer	NOMAD Control — Second
40201	Read	Boolean (bit 0)	A+B — Temperature alarm (yellow: out of tolerance)
40201	Read	Boolean (bit 1)	C+D — Temperature alarm (yellow: out of tolerance)
40201	Read	Boolean (bit 2)	Temperature default (red)
40201	Read	Boolean (bit 3)	A+B — Gas flow rate alarm (yellow: out of tolerance)
40201	Read	Boolean (bit 4)	C+D — Gas flow rate alarm (yellow: out of tolerance)
40201	Read	Boolean (bit 5)	A+B — Gas flow rate default (red: out of gas)
40201	Read	Boolean (bit 6)	C+D — Gas flow rate default (red: out of gas)
40201	Read	Boolean (bit 7)	Condensation default (red: lid unplugged)
40202	Read	Boolean (bit 0)	NOMAD Control — Thermostatic bath default (red: no communication)
40202	Read	Boolean (bit 1)	NOMAD Control — Idle
40202	Read	Boolean (bit 2)	NOMAD Control — Running
40202	Read	Boolean (bit 3)	NOMAD Control — Local (0) / Remote (1)
40202	Read/Write	Boolean (bit 4)	NOMAD Control — Default acknowledgment
40202	Read/Write	Boolean (bit 5)	NOMAD Control — For resetting the PLC clock