Siemens 505-2557 User Manual
Description
1-5
SIMATIC 505–2557 Installation and Operation Guide
RTD inputs exceeding 849.8 degrees C for 100 Ohm platinum or 260.0
degrees C for 120 Ohm nickel and 10 Ohm copper will cause the overrange
bit to be set. A maximum temperature of 849.9 degrees C for 100 Ohm
platinum or 260.1 degrees C for 120 Ohm nickel and 10 Ohm copper will be
returned for any positive overrange input.
degrees C for 120 Ohm nickel and 10 Ohm copper will cause the overrange
bit to be set. A maximum temperature of 849.9 degrees C for 100 Ohm
platinum or 260.1 degrees C for 120 Ohm nickel and 10 Ohm copper will be
returned for any positive overrange input.
Similarly an input below –199.8 degrees C for 100 Ohm platinum or –79.8
degrees C for 120 Ohm nickel or –100 degrees C for 10 Ohm copper will
cause the underrange bit to be set.
degrees C for 120 Ohm nickel or –100 degrees C for 10 Ohm copper will
cause the underrange bit to be set.
NOTE: The SIMATIC 505–2557 uses the least significant bit (16) to indicate
an open RTD. The value of this bit is set to 1 when this condition occurs.
an open RTD. The value of this bit is set to 1 when this condition occurs.
Figure 1-3
Effect of Voltage Input - 100 Ohm Platinum
Figure 1-4
Effect of Voltage Input - 120 Ohm Nickel
Effect of
Out-of-Range Input
Signals
Out-of-Range Input
Signals