ISO 8583

In general, ISO 8583 consists of 3 parts:
1. MTI (Message Type Identifier)
2. Bitmaps
3. Data Elements

We will discuss a little bit. Numbers 1 and 2, which are easy to learn. I am sure you will quickly understand. for number 3 this is a bit difficult.

Because the use of Data Elements can be different from business process or flow or destination, ISO 8583 is different. I’ll explain this section number 3 in general only. To deeper, depending on the case you are facing

1. MTI
For MTI, there are 4 bits. It’s easy. Look at this table
0xxx -> version of ISO 8583 (1987 version)
x1xx -> class of the Message (Authorization Message)
xx1x -> function of the Message (Request Response)
xxx0 -> who began the communication (Acquirer)
The above explanation I took from the wiki. We start from the first bit yes.
So the first bit of MTI is signifying the ISO 8583 version. The value used is

While the second bit of the MTI is to determine the destination message (Message Function) of ISO 8583 itself

of the nine, not all you normally use, most used 1, 2 and 4. 1 can make requests / inquiries. For example, check balances. 2 create a financial transaction, for example pay for PLN, transfer, pay phone bill, etc. 4 make reversal, if for example a transaction fails (eg connection loss that causes time out), then all the transactions will be on rollback (direverse).

Why? Can you pay the electricity bill, the status has been paid off, but when will cut the process of saving, connection loss. so do not kepotong money, then free pay electricity.

That’s why reversal is important too. 8 create network management, echo test. The connection nature of the server to this provider is state full, so the connection is established without breaking, within the specified timeframe it will always send a signal with MTI 0800, and 0810 as the yes-responsen. The 3rd and 4th bits are described below.

Well now enter the 3rd bit of MTI. The 3rd bit is Message Function, just look at the table below

Be patient enough yes. Maybe still dizzy, later finished finished I discuss the new 4th bit you will understand. This 3rd bit marks the ISO 8583 function itself.

klo value 0, then he request, klo 1 then he response. Again, usually the often used is 0 and 1, depending on the case yes. In this case my experience aja. which I see bit 3 if not 0 yes 1 aja. The last bit of MTI is Message Originil, indicating where the ISO Message is.

Again in my experience I usually see just 0 aja. but you must understand all the first. Because your case is different from me. For more details, let’s look at the following simple examples

2. Bitmaps
This part I like best. Why? The problem is short, concise, solid, clear, and easy to understand.
This bit map can be 3 macems, 64, 128, or 192 (the last is very rarely used). The most often it is usually 64, or ga 128. I own 64 ones. I am a 64 example.

if you understand, the same way and the way you read it.
Ok, for example I have a bit map like this (again take example from the wiki): 4210001102C04804
then it means the bits I’m playing are 2, 7, 12, 28, 32, 39, 41, 42, 50, 53, 62. How come? I’m not the origin of guessing. There is a count.

Let’s see together. Look again bit2 earlier, and breaks into small pieces, each consisting of 2 bits.

BYTE1: 01000010 = 42x (42 hexes yes, from left: bit 2 and 7)
BYTE2: 00010000 = 10x
BYTE3: 00000000 = 00x
BYTE4: 00010001 = 11x
BYTE5: 00000010 = 02x
BYTE6: 11000000 = C0x
BYTE7: 01001000 = 48x
BYTE8: 00000100 = 04x

Look at the table above? do you understand? still belom? Okay, look.
BYTE 1: 01000010.
if I count from the left, this number 1 is in the 2nd and 7th digit. Then bit 2 ama 7 I turn to mean. Then BYTE2: 00010000 means bit 12 flame. Calculate not from 1 again, continue that earlier. So if you describe the bit2, dapetnya like this:

0________10________20________30________40________50________60__64 1234567890123456789012345678901234567890123456789012345678901234  n-th bit 0100001000010000000000000001000100000010110000000100100000000100  bit map

The last way is more palatable. bitmaps is easiest right?

3. Data elements
Ok. This is the most complicated part. before getting into the core, you must first understand that data elements carry information from the transaction itself.

The length of its bits can be different, user specified. Depending on the deal you use. Each data element has a default format whose content is defined with different lengths and types.
To understand data elements, first understand this table:

While if the length, can be like this:

Ok, now for example:

Well, then the content of the data element itself please see yourself on the wiki. if the post here stands. Because it buanyak really.
The most important of ISO is:

– data elements 1 contains bitmaps
– bit 3 berisi processing code
– bit 4 berisi amount transaction
– bit 11, stan (system trace audit number)
– bit 18 merchant type
– bit 35: track 2 data
– bit 39: response code, only in the respond
– bit 41: terminal ID
– bit 42: merchant ID
– bit 43: terminal location
– bit 47, 48, 61~63; private bit