Siemens UM344-2 user manual Two-Wire Cable

UM344-2MODEL DESIGNATION AND SPECIFICATIONS

Power Supply
Minimum Compliance Voltage	+12 Vdc with no loop resistance, see Figure 4-4
Network (Current Sense or Loop)
Resistance (RL)	250Ω minimum, 1100Ω maximum
	*RL = 43.4VS - 520.8; where VS = power supply
	voltage
Maximum Loop Voltage	+42 Vdc; for Ex N use, see Section 8.3.6
Ripple	0.2 Vp-p, 47-125 Hz
Noise	0.6 mV RMS maximum
Impedance	10 Ohms maximum
Power Supply Effect	Less than 0.005% of output span per volt
Indication, optional	4-1/2 digit LCD with status indicators
Transmitter Input Capacitance	27,000 pF, HART Cn = 6; refer to section 4.3.5
Network Topology
Point-To-Point
Transmitter Quantity	1
Network Signal and Connection	Analog 4-20 mA, single current loop; see Figures
	4-1 and 4-2
Network Resistance	See Figure 4-4
Multi-Drop
Transmitter Quantity	1 to 15
Network Signal and Connection	Digital, parallel connected; see Figure 4-3
Network Resistance	See Figure 4-4
Transmitter I/O Isolation
Between Input/Output Terminal	250 Vac
Between Case and Networking Wiring	250 Vac
8.3.3 Two-Wire Cable
Type	Twisted Single -Pair, Shielded, Copper
Conductor Size for Network Length
Less than 5000 ft. (1500 m)	24 AWG minimum
More than 5000 ft. (1500 m)	20 AWG minimum, 16 AWG maximum
Cable Capacitance	Refer to Section 4.3.5
Recommendation	Belden 8641, 24 AWG
	Belden 8762, 20 AWG
Length, Maximum	Refer to Section 4.3.5
September 1995	8-9