Aalborg XFM Digital User Manual

Page 32

Several examples of commands follow. All assume that the XFM has been con-
figured for address 18 (12 hex) on the RS485 bus:

To get current calibration tables:

!12,G

The XFM will reply:

!12,G 0 AIR >

(Assuming Current Gas table is #0, calibrated for AIR )

To get current Alarm status:

!12,A,R

The XFM will reply:

!12,N (Assuming no alarm conditions)

To get a flow reading:

!12,FThe XFM will reply:
!12,50.0 (Assuming the flow is at 50% FS)

Set the high alarm limit to 85% of full scale flow rate:

!12,A,H,85.0

The XFM will reply:

!12,AH85.0

The global address can be used to change RS-485 address for a particular device with
unknown address:

Make sure only one device (which address must be changed) is connected to the
RS-485 network.

Type the memory write command with global address: !00,MW,7,XX[CR] where
XX, the new hexadecimal address, can be [01 – FF].

After assigning the new address, a device will accept commands with the new address.

Note: Address 00 is reserved for global addressing. Do not assign, the
global address for any device. When command with global address is
sent, all devices on the RS-485 bus execute the command but do not
reply with an acknowledge message.

Note: Do not assign the same RS-485 address for two or more
devices on the same RS-485 bus. If two or more devices with the same
address are connected to the one RS-485 network, a communication
collision will take place on the bus and communication errors will occur.