General

How do I connect multiple devices together

This article contains information about how to connect IASI devices together

Is it possible to connect multiple devices to a PC COM port?

Yes but only for transmission to the device, you can connect the output of the com port (Pin 3) to multiple devices on pin 4 of the IASI interface BUT you can only connect ONE device for input to the COM port.
To receive from multiple devices you need to use a BV101-4 (USB).

When connecting multiple devices how is it possible to differentiate between them?

Each device can have its own unique address, this must first be set using the 'A' command on an individual basis, i.e. before connecting them together.

Can I tell what the addresses are when several devices are connected?

Yes, command 1 will return the address followed by the prompt of each device on the bus. A typical output would be a>f>y> for 3 devices with addresses 'a', 'f' and 'y'. This will take almost 1 second as each device waits its turn to send the address information.

I am having problems sending commands from a program

The symptoms of this are erratic behaviour or the device does not respond to commands yet it works perfectly well with the terminal program. The problem is usually that the complete packet has no been sent or additional characters within the packet are being sent. A packet consists of:

The usual fault is to either forget to terminate the packet with 13 (CR or vbCR) or the program may automatically put <10><13> on the end of the line. This will cause problems as the 10 will be interpreted as part of the data.