240 Series specifications

Input specifications

Standard inputs (normal mode, reversing¹)

	Sensor temperature coefficient	Input range	Excitation current	Display resolution	Measurement resolution	Electronic accuracy (at 25 °C)	Measurement temperature coefficient
Diode	Negative	0 V to 7.5 V	10 µA ±0.05%	100 µV	20 µV	±320 µV ±0.01% of rdg	(20 µV + 0.0015% of rdg)/°C¹
PTC RTD 1 mA	Positive	0 Ω to 1 kΩ	1 mA	10 mΩ	20 mΩ	±0.04 Ω ±0.02% of rdg	(1 mΩ + 0.0015% of rdg)/°C¹
NTC RTD 10 mV	Negative	0 Ω to 10 Ω	1 mA	0.1 mΩ	0.1 mΩ + 0.002% of rdg	±0.002 Ω ±0.06% of rdg	(0.1 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 30 Ω	300 µA	0.1 mΩ	0.3 mΩ + 0.002% of rdg	±0.002 Ω ±0.06% of rdg	(0.1 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 100 Ω	100 µA	1 mΩ	1 mΩ + 0.002% of rdg	±0.01 Ω ±0.04% of rdg	(0.1 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 300 Ω	30 µA	1 mΩ	3 mΩ + 0.002% of rdg	±0.01 Ω ±0.04% of rdg	(0.3 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 1 kΩ	10 µA	10 mΩ	10 mΩ + 0.002% of rdg	±0.01 Ω ±0.04% of rdg	(1 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 3 kΩ	3 µA	10 mΩ	30 mΩ + 0.002% of rdg	±0.01 Ω ±0.04% of rdg	(3 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 10 kΩ	1 µA	100 mΩ	100 mΩ + 0.002% of rdg	±1.0 Ω ±0.04% of rdg	(10 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 30 kΩ	300 nA	100 mΩ	300 mΩ + 0.002% of rdg	±2.0 Ω ±0.04% of rdg	(30 mΩ + 0.0015% of rdg)/°C¹
		0 Ω to 100 kΩ	100 nA	1 Ω	1 Ω + 0.002% of rdg	±10.0 Ω ±0.04% of rdg	(100 mΩ + 0.0015% of rdg)/°C¹

¹ Current reversal used only for resistive ranges
² Rated temperature coefficient from 15 °C to 35 °C, reduced accuracy from -20 °C to 50 °C

	RTD	Diode
Measurement type	4-lead differential	4-lead differential
Excitation	Constant current with current reversal	10 µA constant current
Supported sensors	Cernox^®, platinum, germanium, carbon-glass, rhodium-iron, and Rox™	Silicon, GaAlAs
Standard curves supplied	LSCI PT-100, IEC PT-100, IEC PT-1000	LSCI DT-670 LSCI DT-470
Input connector	5-pin terminal plug	5-pin terminal plug

Number of inputs	2 (Model 240-2P) 8 (Model 240-8P)
Isolation	Sensor inputs isolated from other circuits but not each other
Input accuracy	Sensor dependent, refer to Input Specifications table
Measurement resolution	Sensor dependent, refer to Input Specifications table

¹ Update rate is halved when an input is on the 100 kΩ range with current reversal enabled

² All inputs enabled

³ Filter settings are tied to the update rate (filter = 1000/update rate)

Temperature conversion	Lake Shore calibration curves (linear interpolation)
User curves	Each input has storage for one 200-point curve
Reporting units	K, °C, °F, V, Ω

Protocol	DP-V0
Baud rates	9.6 k, 19.2 k, 45.45 k, 93.75 k, 187.5 k, 500 k, 1.5 M, 3 M, 6 M, 12 M (auto baud-rate detect)
Identification number	0x0F84
Reading data format	Single precision float (32-bit)
Reading rate	Matches update rate of the instrument

Function	Emulates a standard RS-232 serial port
Baud rate	115,200, 8 data bits, 1 stop bit, no parity, no handshaking
Connector	USB micro-B
Reading rate	Matches update rate of the instrument

Module configuration	Module configured over USB interface
Configuration software	MeasureLINK™ ( free download, supported on Windows 7, 8, and 10)
Firmware update	Firmware updated over USB port

Temperature display resolution	0.0001° from 0° to 9.9999°, 0.001° from 10° to 99.999°, 0.01° from 100° to 999.99°, 0.1° above 1000°
Sensor units display resolution	Sensor dependent, to 5 digits
LED annunciators	Module status and communication status

Connection	Screw terminal
Voltage requirement	24 VDC, ±10%
Current requirement	100 mA per connected module
Power distribution	Maximum 20 units connected through the DIN rail backplane connector (power supply must be able to source required current)
Internal protection	Over-voltage, under-voltage, and reverse polarity protection

Case material	Polyamide
Mounting	35 mm DIN rail (EN 50022)
Water ingress	IP20: not protected against harmful ingress of water
Case inflammability	Class V0 according to UL 94
Sensor connector wire size	16 to 28 AWG
Power connector wire size	12 to 24 AWG
Size	22.5 mm W × 115 mm H × 100 mm L (240-2P) 90 mm W × 115 mm H × 100 mm L (240-8P)
Weight	120 g (240-2P) 300 g (240-8P)

Compliance	RoHS; CE
Operating temperature	15 °C to 35 °C at rated accuracy, -20 °C to 50 °C at reduced accuracy
Storage temperature	-40 °C to 85 °C
Relative humidity	0 to 70% at rated accuracy, reduced accuracy up to 95%, non-condensing