multicharts-fundamentals

name	multicharts-fundamentals
description	Use when orienting on the MultiCharts platform — choosing Indicator vs Signal vs Function, bar-close vs intra-bar-order-generation execution, multi-data references (data1, data2), Buy/Sell/SellShort/BuyToCover orders, and the unique-signal-name compile rule.

MultiCharts Fundamentals

What MultiCharts is

MultiCharts is a Windows trading platform from MCT Limited (Gibraltar). It connects to multiple data feeds and brokers, runs technical analysis and discretionary trading from charts and DOM, and executes algorithmic strategies written in PowerLanguage. It also includes QuoteManager (local market-data storage) and Market Scanner (multi-symbol monitoring).

What PowerLanguage is

PowerLanguage (PL) is the scripting language inside MultiCharts. Source code is edited inside the PowerLanguage Editor and stored in MultiCharts's internal studio database — it doesn't have a standalone source-file extension. Exported study bundles use the .pla extension (PowerLanguage Archive — a ZIP-based binary format), and these are brought into another machine via PowerLanguage Editor → File → Import. When sharing or pasting raw source code outside the studio, plain text (.txt) is the convention. PowerLanguage is functionally compatible with TradeStation's EasyLanguage — most EasyLanguage scripts run unmodified in MultiCharts, and MultiCharts adds keywords of its own (the pmms_* portfolio money-management family, MC_TL_*/MC_Arw_* drawing variants, RecoverDrawings, ProcessMouseEvents, …) that don't exist in EasyLanguage.

Key characteristics:

• Pascal-flavored syntax (begin/end blocks, semicolon statement terminators).
• Event-driven: the entire script runs top-to-bottom on each bar close (or on each tick when IOG is enabled).
• Compiled by the PowerLanguage Editor; can call external DLLs for C++ / VB integration.

Editions

Edition	Language	Notes
MultiCharts (Standard)	PowerLanguage	The original; what most users mean by "MultiCharts"
MultiCharts .NET	C# / VB.NET	Same engine, .NET 4.8 hosting, real-time debugging in Visual Studio
MultiCharts Portfolio Trader	PowerLanguage + portfolio APIs	Multi-instrument backtesting & live trading module

This skill covers Standard (PowerLanguage). The .NET edition uses different language but the same platform concepts apply.

The three script types

Every PowerLanguage script is exactly one of these:

• Indicator — visual analysis. Can Plot1, draw trendlines, paint bars, display text. Cannot issue orders.
• Signal — automated trading logic. Can Buy, Sell, SellShort, BuyToCover. A Strategy in MultiCharts is one or more Signals applied to a chart; each Signal contributes orders.
• Function — reusable calculation. Returns a value by assigning to its own name: MyFunc = result;. Called from Indicators, Signals, or other Functions.

A Signal can't plot. An Indicator can't trade. A Function can't do either; it just returns a number, boolean, or string. Picking the right script type before you start writing avoids large rewrites.

How scripts execute

By default, a Signal script runs once per bar, at the bar's close (and on every historical bar). References like Close[1] mean "the close of the bar before this one." Order placement keywords schedule orders for the next bar — Buy ... Next Bar at Market is the standard idiom, and it fills at the next bar's open, not the signal bar's close. Note: real-time Indicators recalculate on every incoming tick by default ("Update on every tick" in study properties) — bar-close-only execution is the Signal default, not a platform-wide rule.

For tick-level execution, enable Intra-bar Order Generation (IOG) in script properties. With IOG on, the script runs on every incoming tick, and the values of Open/High/Low/Close reflect the developing bar in real time. IOG is needed when you want orders that depend on intra-bar price changes (e.g. stop-orders that should fire as soon as price touches a level, not at the next bar close).

Multi-data series

A chart can host more than one data series — data1 is the primary, data2/data3/… are additional series mapped through chart properties. Access them by suffix:

Close of data2          // close of the second series
Average(Close of data2, 20)

Common uses: pair-trading (data2 = the second leg), regime filters (data2 = a higher-timeframe series of the same instrument), or cross-market signals (data2 = a related contract).

Order keywords (Signal scripts only)

• Buy — opens a long position. If currently short, the fill closes the short and reverses to long in one order (official docs: "When a Buy order is filled, any open short positions will also be closed"). Adds to an existing long only if pyramiding is enabled in Strategy Properties — off by default, so a second Buy while already long is ignored.
• Sell — exits a long position. Never opens a short.
• SellShort — opens a short position. If currently long, the fill closes the long and reverses to short. Same pyramiding rule as Buy.
• BuyToCover — exits a short position. Never opens a long.

General shape:

Buy ( "EntryLabel" ) <quantity> Contract[s]|Share[s] Next Bar at Market;
Buy ( "EntryLabel" ) <quantity> Contract[s] Next Bar at <price> Limit;
Buy ( "EntryLabel" ) <quantity> Contract[s] Next Bar at <price> Stop;
Buy ( "EntryLabel" ) <quantity> Contract[s] This Bar on Close;

Each form is documented in detail in the powerlanguage-keywords-reference skill — invoke that for full signatures and parameter rules.

The unique-signal-name compile rule

Every order name within one Signal script must be unique. If you write:

Buy ("LE") 1 Contract Next Bar at Market;
// ... later ...
Buy ("LE") 1 Contract Next Bar at 100 Stop;

…the script will not compile. MultiCharts uses the order name string to track which order produced which fill, so duplicate names are rejected at compile time. Pick distinct labels — "LE_Market" and "LE_Stop", or "LE" and "LE_Pyramid". This rule applies to all four order keywords (Buy, Sell, SellShort, BuyToCover), and is enforced per-Signal — two different Signals on the same chart can each have their own "LE".

When to invoke other skills

• powerlanguage-syntax — for grammar questions: semicolons in begin/end, control flow, declarations, common gotchas.
• powerlanguage-keywords-reference — for any specific keyword: signature, parameters, what category it belongs to.