2. Transaction Procedure

Where a user has the Dealing 2000 System installed, there are Dealing 2000 Servers installed, each of which serves twelve Dealing 2000 terminals. These terminals allow dealers to conduct conversations with other dealers at other banks and to conclude deals with them. Dealing 2000 extracts the deal data from the conversation.

All ASI deals are routed through one ASI concentrator, so the mix of serial lines attached to a D2ASI system may be up to three Dealing 2000s and one ASI.

2.1 Deal completion

When a deal has been completed, the deal machine informs the D2ASI that a deal has been added to the list of outstanding deals completed. The D2ASI calls off the deals (in the case of D2000, not more frequently that every five seconds, in order to avoid overloading the Dealing 2000 Server)

2.2 D2ASI processing

D2ASI files all entered deals in its audit trail twice. When the deal is received, the Reuter record is filed in a file with the extension .ATI . Itis queued in memory pending a request for data from TFS. When the deal is about to be transmitted to the TFS system, the details of the deal are recorded in plain English to a file with the extension .ATO. The first part of the file name is the date in the format MAR2594, where 94 is the year.

The memory queue is 150 deals long (memory limited) and, if a longer queue is built up, this is done by transferring the oldest deal to the BATCH file. This is transparent to TFS except that the deals in memory are exhausted before the BATCH deals are transmitted, so the deals will not be in dealing order. Normally, it should never happen that deals are written to a BATCH file.

The TFS system calls off deals with a QUERY message and will get the oldest deal. If there is no deal available, the TFS system will receive an error message with a positive error code of GOOD_NDA for 'no deal available'. It should then time out before sending another request.

2.3 TFS processing

The deals are returned to TFS in the form of structures defined by TFS.

2.4 Physical arrangement

2.4 1 Serial ports

Each D2ASI can serve up to three Dealing 2000 Concentrators, assuming that the bank has the maximum of 32 users and one ASI. If a D2ASI has more than two concentrators attached, it will need a Digiboard PC-4 multi-serial card and it is necessary for all the Dealing 2000 concentrators to be attached to the Digiboard. The system automatically configures itself for the number of Dealing 2000 concentrators attached, using the information in the D2ASI.CNF file (see below). Do not attempt to use different types of serial port. You can use serial ports with 16550 UARTs or 8250 type UARTs but not mixed.

2.4.2 Connection to TFS

D2ASI is connected to the TFS system by the dealing room LAN. ASL have supplied TFS with their LAN user's Application User Interface (ASL-API below), which makes using a LAN as simple as reading and writing to a file. This system uses Novell IPX as a transport medium and both systems need IPX or IPXODI available. This is a Novell TSR and IPXODI needs a separate LAN card driver. If these software items are not available on-site at the bank in which the system is to be installed, the simplest way of acquiring them is to purchase two copies of Novell Personal Netware (or, if it is still available, Netware Lite, which is a little cheaper) to obtain licenced copies of the drivers. ASL will perform this for users at cost (i.e. a day's work and travel costs).