📦 Archived documentation: r1 (committed 2026-07-24) View current documentation →

bin.alloc()

bin.alloc(bytes) → buffer

Allocates a empty buffer (string) that can be used to store and read binary values.

Creates an empty string bytes long. String objects in mJS are byte strings, so they can hold arbitrary binary data — null characters do not terminate them. After any call to bin.alloc() the binary read/write cursor is automatically positioned at the start of the new buffer.

Arguments

NameTypeRequiredDefaultDescription
bytes number yes Buffer size in bytes — 4 bytes per 32-bit register/float.

Returns

string A buffer with seek/read/write methods, cursor positioned at byte 0.

Example

let mbData = bin.alloc(20*4); // room for 20 float registers
modbus.setData(mbData); // Assign the data buffer for to modbus read and write requests.

while(run()){


mbData.write("F32ABCD",75); // Write a float32 (4 bytes) to our modbus data table
waitMS(1000);

}