4 dp command (diagnostic poll), 5 ca command (change address) – Tyco MX4428 User Manual

Page 105

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Document: LT0273

MX4428 MXP Engineering / Technical Manual

MXP

Diagnostic

Terminal

Issue 1.5

24 March 2006

Page 8-7

8.1.6.4

DP Command (Diagnostic Poll)

This command lists all the devices found (irrespective of the MX4428 programming) by
issuing a command to each side of the loop (left and right) which requests all devices to
identify themselves. Thus it can be used to find what devices are present on the loop and
which devices are found from each end, if the loop is broken or isolator bases have opened.
This can help identify which section of the loop cable is broken or shorted.

It will list devices found with any address including addresses above 200. If two or more
devices are present with the same address they will usually be detected, however their
replies may collide resulting in neither being detected. Therefore a second attempt is made
on each line in order to maximise the chance of locating multiple devices with the same
address. On the second attempt, only devices not found on the first attempt are displayed.

This command is a local version of the MX4428 DP command.

>>dp
>>Diagnostic Pollscan line 1
Scan attempt 1
Adr 2 : CO/Heat
Adr 3 : Heat Only
Adr 20 : Ionisation Foreign (not programmed)
Adr 21 : MIM
Adr 22 : CP
Adr 23 : CIM
Adr 24 : RIM
Adr 25 : DIM
Adr 26 : SNM
Scan attempt 2
Diagnostic Pollscan line 2
Scan attempt 1
Adr 2 : CO/Heat
Adr 3 : Heat Only
Adr 20 : Ionisation
Adr 21 : MIM
Adr 22 : CP
Adr 23 : CIM
Adr 24 : RIM
Adr 25 : DIM
Adr 26 : SNM
Scan attempt 2
Diagnostic pollscan complete

The DP command will note as “foreign” any devices which are found but not currently
programmed. However it will not display devices which are programmed but not found.
Other messages may be given, e.g. “Duplicate Device”, “Unknown Type”, “Used as Heat
only”, “Used as MIM”, “Type Mismatch”.

8.1.6.5

CA Command (Change address)

The change address command may be used to change the address of a single device (the
first number) on the analog loop to a new address (the second number). If devices are
added one at a time, this command may be used to assign their addresses instead of using
the programming tool. New devices from the factory normally have an address of 255.

Both new and old addresses may be any number greater than 0 and up to 255. Addresses
between 201 and 255 will be inaccessible to the MX4428.

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