Siemens Sitrans Application level indicator and solid-state switch output, Appendix E, 90.0, 08.0

Application: level indicator and solid-state switch output

The loop current provides:

•a reading proportional to level, within the 0 - 100% range, at menu 00 or 10 on the device, or at a remote indicator

•an out-of-range signal ooL alternating with PV if the level is above URV or below

LRV

The solid-state switch is activated at Upper Threshold Setting and deactivated at Lower Threshold Setting. In the diagram below, it is used to activate a pump via an auxiliary power circuit.

•The activation and deactivation can be modified by Upper and/or Lower Threshold delays (menus 13 and 14).

•The reading can be stabilized if necessary by applying Damping (menu 0A): the update value for Damping is controlled by menu 09.

Example: The level is to be held between 90% and 8%.

	Indicator: primary variable viewed at menus 00 or 01;
	0-100%units or% selected in menu 01		auxiliary
		solid-	power
			pump
	current loop connection	state
	Active Shield section	output	power
		P
	(menu 0C) USL	75.8 pF
	(menu 0F) URV = 100%
	Upper Threshold Setting = 90%
solid-state	menu 15 (activation hysteresis)
switch
output:
selected at
menu 17	menu 16 (deactivation hysteresis)
and
	Lower Threshold Setting = 8%
controlled		14.3 pF
	(menu 0E) LRV = 0%
by menus
13 to 18.	(menu 0B) LSL

Device settings:
(The device is first restored to factory settings before being commissioned)
TV0 selected: Transmitter Variable 0 is PV	Menu 01 reads	Pv = 0
Lower Range Value (0% of range) is set to 14.3	Menu 0E reads	14.30
Upper Range Value (100% of range) is set to 75.8.	Menu 0F reads	75.80
Current loop is in analog mode, with both buttons pressed	Menu 07 reads	C:An
Solid-state switch enabled, contact closed selected	Menu 17 reads	S:cc1
Activation hysteresis is set to 90.	Menu 15 reads	90.0
Deactivation hysteresis is set to 8.	Menu 16 reads	08.0.

When the level reaches 90%, the solid-state output is closed and the pump is started via the auxiliary circuit. When the level drops to 8% the solid-state output is opened, the auxiliary circuit is deactivated, and the pump stops.

1.S:cc appears while the button is pressed. See menu 17 on page 70 for more details.

7ML19985GE01 SITRANS LC 500 – INSTRUCTION MANUAL Page 93

Appendix E