XBee not discovering numeric Node Identifiers

I have two XBee 900HPs and want one to use the AP Command “DN” (Discover Node) to discover the other.

When the Node Identifier I wish to find is entirely numeric I am returned data that doesn’t make sense. For example, “1234” does not work, while “ABC”, “AB1” and “1BC” do. Numeric NIs can be discovered when using X-CTU but not my software, and I can’t find any explanation.

If I search for the device “1234”
Out: 7E 00 08 08 01 44 4E 31 32 33 34 9A
(7E, length MSB, LSB, Frame, Frame ID, ‘D’, ‘N’, ‘1’, ‘2’, ‘3’, ‘4’, checksum)
In: 7E 00 08 28 44 4E 31 32 33 34 9A

The issues: Frame type 28 isn’t used in Digimesh, and is returning exactly what I put in (length, NI and checksum being sent are coming in, instead of the device’s serial number.)

Both devices are set to API Mode with No Escapes, and the NIs are changed appropriately for each device I want to test. Works as advertised for nearly all packets with letters in them, as far as I can tell. I am not accidentally beginning my NI with a space. Does anyone have suggestions for why this might be happening or what the source could be?

The NI command and value are ASCII values up to 20 characters long. Could it be that your application is reading Hex values instead of ASCII?

All I am doing is taking the number and printing them straight out (I believe the number comes in as Hex, printing defaults Dec). I make sure my software considers the values to be representing ASCII characters. The incoming byte for a ‘0’ character would be ‘0x30’ or 48, correct? That seems to be how it works for non-numeric NI’s. I don’t think this is the issue, but I’ll check this over at least. (Additionally, my NI is kept within that character limit.)