Expansion modules are used as communication interfaces for 7KT PAC1500 measuring devices. They have the following features:

• The expansion modules can be selected independently of measuring device. These can also be retrofitted to existing measuring devices.
• Data transmission between the measuring devices and expansion modules is executed via the IrDA infrared interface.
• The expansion modules are placed alongside the measuring devices in the installation direction so that their IrDA interfaces are exactly opposite each other.