Siemens M7-400 ユーザーズマニュアル

5-118

S7-400, M7-400 Programmable Controllers Module Specifications

A5E00069467-07

If you have select “current (two-wire transmitter)” for channel 6, you can only
disable the measuring method or set “current (two-wire transmitter)” for channel 7.

The following conditions apply when measuring the resistance and temperature
with the SM 431; AI 16 x 16 Bit:

Table 5-67 Channels for Resistance and Temperature Measurement of the SM 431; AI 16 

 

 16 Bit

Resistor 
(four-conductor terminal)

0, 2, 4, 6, 8, 10,
12 or 14

You must disable the 

(

“Measuring Type” parameter

for channels n+1 (1, 3, 5, 7, 9, 11, 13, 15).

Resistor 
three-conductor terminal

0, 2, 4, 6, 8, 10,
12 or 14

( , , , , ,

,

,

)

The reason The connections of channel n+1 are used
to supply the resistance that is connected to channel

Thermal resistor
(linear, four-conductor termi-
nal)

0, 2, 4, 6, 8, 10,
12 or 14

pp y

n.

Thermal resistor
(linear, four-conductor termi-
nal)

0, 2, 4, 6, 8, 10,
12 or 14

Thermocouple (linear)

0 to 15

You can select the reference junction. It is only
advisable to specify a reference junction with
thermocouples.

If you select “RTD on Channel 0” as a reference junction for reference junction
compensation for thermocouples, the following applies:

Table 5-68 Reference Junction Compensation via RTD on Channel 0 of the SM 431; AI 16 

 

 16 Bit

RTD on Channel 0

2 to 15

You must connect and parameterize on channel 0 a
resistance thermometer with linearization, a 3- or
4- conductor terminal in climatic range. This means that
channels 0 and 1 are assigned.

The reason If channel 0 is to be used as the reference
junction, a resistance-type sensor must be connected
there to establish the absolute temperatures in the
climatic range.