What Is Baan Session?
Also known as: LN session, session code, Baan session code
Definition
A Baan session is the atomic executable unit of Baan and Infor LN - one screen, report or batch program - identified by a coded name such as tdsls4101m000, where the letters give the package and module and the digits give the session number.
Baan Session Explained
Every user-facing function in Baan and Infor LN is a session. Maintaining sales orders is a session, printing a picking list is a session, running a planning job is a session. Each one is defined in the Tools data dictionary with a form layout, a main table, a set of authorized commands and a 4GL script that supplies the behavior. Because sessions are first-class objects, they are also the unit of authorization, of menu placement and of customization.
The naming convention is what makes the system navigable. A code like tdsls4101m000 breaks down as a two-character package (td for distribution), a three-character module (sls for sales), a four-digit session number, a letter indicating the session type, and a three-digit version. The trailing letter distinguishes categories such as a multi-occurrence maintenance session from a single-occurrence session, and the number ranges group display, maintain, print and process functions in a broadly consistent way across modules.
Experienced practitioners work by code rather than by menu. Support tickets, documentation and consultant conversations all reference session codes because they are unambiguous across languages and menu configurations. Most environments let a user start a session directly by typing its code, which is far faster than navigating a menu tree and is essential when following written instructions that were produced for a differently configured site.
Sessions also matter technically. Customization historically meant modifying a standard session's script in a derived VRC, which is precisely what makes upgrades expensive. The modern LN approach attaches extension code to defined points on the standard session instead, leaving the standard object untouched. When someone asks how customized an environment is, the honest answer is a count of modified sessions and extended sessions, not a subjective description.
Why It Matters
- Session codes are the universal language of Baan and LN support, so knowing them cuts diagnosis time dramatically.
- Authorizations are granted per session, making the session list the practical basis for segregation-of-duties design.
- Counting modified sessions per VRC is the fastest reliable measure of customization debt before an upgrade.
- Running sessions directly by code bypasses menu misconfiguration, which is often the quickest workaround during an incident.
In Practice
When a user reports that a screen is missing, resolve it by code rather than by menu. Ask them to start the session directly. If it runs, the problem is menu or DEM configuration; if it is refused, the problem is authorization. That single test separates two very different root causes in under a minute.
Frequently Asked Questions
How do I read a Baan session code?
Read it left to right. The first two characters are the package, such as td for distribution or tf for finance. The next three are the module, such as sls for sales. The four digits are the session number within that module, the following letter indicates the session type, and the final three digits are the version. So tdsls4101m000 is a distribution, sales, session number 4101.
Can users run sessions directly by code?
Yes, provided they are authorized for that session. Both the classic and web interfaces offer a way to start a session by entering its code, and support teams rely on this constantly. Authorization is still enforced, so running by code is a navigation shortcut rather than a security bypass. If the session is refused, the user simply lacks the authorization.
Related Terms
Baan 3GL and 4GL
Baan 3GL and 4GL are the two programming languages of Baan and Infor LN. 4GL is the event-driven script attached to a session and its form fields, while 3GL is the C-like language used for libraries, DAL objects and standalone programs.
Baan/LN Tools Package
The Tools package is Baan and Infor LN's own development and administration layer. It holds the data dictionary, session and form definitions, the 3GL and 4GL compilers, VRC software layering, authorization management, job scheduling, company setup and the Exchange module.
LN Extensions
LN Extensions are Infor LN's supported customization framework: extension scripts and objects attached to standard sessions, tables and business logic through defined extension points, stored outside standard code so vendor upgrades and cloud updates do not overwrite them.
Go Deeper
Baan to Infor LN Migration Readiness Assessment
Score your organization's readiness to migrate from Baan IV or Baan V to Infor LN across ten dimensions, from data quality to executive sponsorship.
Infor LN Studio Development: Extensions Without Upgrade Pain
Infor LN Studio development guide: 4GL sessions, DALs, LN Extensions, and CDFs - how to customize LN without source modifications that break upgrades.
Baan 4GL Modernization: Strategies for Legacy Code
Baan 4GL modernization strategies: inventory legacy sessions, retire dead code, convert customizations to LN extensions, and de-risk your Baan installed base.
Working with Baan Session in a live environment? Our engineers do this every day - and our AI agents automate most of it.
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Infor LN Session and Module Code Reference
Searchable list of the Infor LN / Baan package and module codes (tisfc, tdsls, whinh and others) with what each one covers.
New to Infor LN and Baan? Start with the Infor LN and Baan guide and toolkit, or plan with Training Path Builder, Upgrade Path Planner, ERP Table and Field Explorer.
Keep exploring
Free tools
- Infor LN Session and Module Code ReferenceSearchable list of the Infor LN / Baan package and module codes (tisfc, tdsls, whinh and others) with what each one covers.
- Infor LN and Baan ERP Table List by PackageFilterable list of commonly used Infor LN and Baan tables by package, with the naming convention, key fields and where a Baan IV table differs from LN.
- Infor LN 4GL Session Script TemplateGenerate a clean Baan / Infor LN 4GL session script skeleton with declaration, field, choice and table I/O sections.
ERP fixes and how-tos
- Cannot Find Session Info in Baan and Infor LN: Causes and FixFix the cannot find session info error in Baan and Infor LN: session missing from the VRC or runtime dictionary, package mismatch, and how to reconvert.
- How to create a custom session in Infor LN StudioBuild a custom maintenance or overview session in Infor LN Studio from a table, wire up authorization and menus, and deploy it safely through your VRCs.
- Infor LN Not Authorized to Run This Session: How to Fix ItInfor LN blocks a user with a not authorized to run this session message. Here is what the authorization check verifies and how to grant access fast.
Guides
- Infor LN Session Programming GuideComplete guide to Infor LN session programming. Session architecture, form design, data handling, and business logic implementation for LN developers.
- AI Integration with Infor LN and Baan: A Technical GuideIntegrate AI with Infor LN or Baan: ION API patterns, business object documents, session versus web service access, and where AI agents should not write.
- Building and Modifying Infor LN Sessions: Developer GuideLearn to create and modify Infor LN sessions including form design, field triggers, choice fields, zoom sessions, and session-to-session communication patterns.
Integrations
- How to add AI agents to Baan IV and Baan VHow to add AI agents to Baan IV or Baan V: tool layer over read-only database access and AFS, human approval on writes, and an on-prem model. A practical guide.
- How to use ChatGPT with Baan IV and Baan VUsing ChatGPT with Baan IV or Baan V: exports versus live access, custom GPT actions, enterprise data controls, and when a private on-prem model is the safer choice.