ISO8583 message decoding

Question

I am just beginner to ISO 8583 messaging format.

So, i already search information about that at WIKI and Code Project

So as i understand about that is..

this message we can divide 3 parts ...

1.MTI (Message Type Indicator)
     1.1.Version
     1.2.Message Class
     1.3.Message Function
     1.4.Message Origin
2.Bitmap
     Indicate which data elements are present.
3.DataElement

The essence of the whole ISO message, contain information about the transaction such as ...

• transaction type,
• amount,
• customerid

and so on.

So, After i reading these two web references, I want to make divide my ISO messaging log as MTI, bitmap, and Data Element.

For example.

 (0800 2020000000800000 000000 000001 3239313130303031)
MTI: 0800 (1987 version, Network Management Message, Request, Acquirer)
Bitmap: 20 20 00 00 00 80 00 00 (eg. 20 = 0010 0000 ,so position 3 is on) 
DataElement:(by seeing Bitmap , we can defined data element as follow)
     field 03:000000 (Processing Code)
     field 11:000001 (Systems trace audit number)
     field 41:3239313130303031 (Card acceptor terminal idenfication)

But my problem is, I already have ISO 8583 messaging log from my ATM Machine. This actual output messaging log is not very clear like this upper example. So I cannot divide this message to MTI, Bitmap and Data element like upper example.

Here are my Example of data

00 14 5e 47 2e d8 00 1a d4 0c 32 0f 08 00 45 00 
00 7b b2 ec 40 00 80 06 e5 29 ac 11 05 37 ac 11 
05 0d 1a 78 1a 78 bf 1c 66 c8 8f 11 b5 a9 50 18 
3f b6 c8 f6 00 00 00 51 31 31 1c 30 30 32 1c 1c 
1c 31 3b 1c 3b 35 32 36 34 30 32 31 37 30 33 32 
36 34 30 32 34 3d 31 34 30 35 32 32 31 31 30 30

Answer 1

What you have there as a sample is just the representation of the transaction info as it's transmitted over the wire. This is effectively the way all data transmission looks like at the transport layer, regardless of application.

Depending on the terminal management application/switch you're using (Postilion and Base24 are good examples), there should be a translation of that hex payload into ASCII text somewhere in your logs.

For the sample you have, you should first convert it to binary and then convert the binary result to ASCII. Using those steps, I can tell you the Institution Identifier Number (or Bank Identifier Number) in that sample is 526402. The snippet you've posted contains the Track 2 data, which also has the PAN in it. I'm not posting that here for obvious reasons (I'm not even going to apply the masking to it)