Siemens SIMATIC S7-300 Module data Reference Manual

Analog Modules
4-61
Programmable Logic Controllers S7-300 Module Data
A5E00105505-03
Connection of thermocouples with internal compensation
Connect the thermocouples to the inputs of the module, either directly or by means
of compensating lines. Each channel group can use a thermocouple type
supported by the analog module independently of the other channel groups.
M+
M–
M+
M–
ADC
M
L+
COMP–/M
ANA
COMP+
Compensating leads
(same material as
thermocouple)
Backplane
bus
K7
K0
.
.
.
Thermocouple
Logic
Figure 4-23 Connection of Thermocouples with Internal Compensation to an
Isolated AI
Connecting the compensating box
Connect the compensating box to the COMP terminals of the module, locating the
compensating box at the reference junction of the thermocouples. The
compensating box must have an isolated supply. The power supply must have
adequate filtering, for example by means of a grounded shielding winding.
The terminals for connecting the thermocouple to the compensating box are not
required and must therefore be shorted (refer to Figure 4-25 for an example).
The following constraints apply:
• The parameters of a channel group are general valid for all channels of that
group (for example, input voltage, integrating time etc.)
• External compensation with connection of the compensating box to the COMP
terminals of the module can be performed only for one thermocouple type. In
other words, all channels operating with external compensation must use the
same type.

Siemens SIMATIC S7-300 Module data Specifications

General

Series	S7-300
Manufacturer	Siemens
Protection Class	IP20
System	SIMATIC S7-300
Digital Inputs	Varies by module
Digital Outputs	Varies by module
Analog Inputs	Varies by module
Analog Outputs	Varies by module
Central Processing Unit	Varies by CPU model
Supply Voltage	24V DC or 120/230V AC
CPU Type	Varies (e.g., CPU 312, CPU 315, etc.)
Memory	Varies by CPU model
Communication Interfaces	MPI, PROFIBUS
Programming Languages	LAD, FBD, STL, SCL, GRAPH
Operating Temperature	0°C to 60°C
Storage Temperature	-40°C to 70°C
Relative Humidity	10% to 95% (non-condensing)