Biamp MSP RS-232 User Manual

RS-232 Control

of the

Advantage MSP11/MSP22

.

Biamp Systems, 10074 S.W. Arctic Drive, Beaverton, Oregon 97005 U.S.A. [phone]

an affiliate of Rauland-Borg Corp.

Introduction

This document contains information for the serial control of the Advantage MSP11 and
the Advantage MSP22. Specifically, this document tries to inform those looking to write
their own software controls for the Advantage MSP (in this document, the term
“Advantage MSP” refers to both the MSP11 and MSP22). It is assumed that the reader
has some familiarity with standard programming practices, binary and hexadecimal
numbers, the ASCII character set, asynchronous serial data connections, and RS-232
interfaces.

Decimal, Binary, and "Pseudo-hex" Numbers

This document uses three different numerical notations. The first is the decimal notation.
Whenever it is used, a “d” will appear after the number..

8 Bit binary numbers are the second format used in this paper. These numbers will be
followed by “b” after their usage. If a specific bit is being referred to, the numbers will
be preceded by the word “bit.”

To transmit an 8 bit binary number to the Advantage MSP, hexadecimal notation is used.
Hexadecimal numbers are arrived at by splitting the number into two halves. One half
consists of the first four binary digits (most significant nibble) while the other consists of
the last four binary digits (least significant nibble). 2 nibbles form a byte, which takes on
a decimal value of 0 to 255. Each half is then assigned a hexadecimal value. Since the
binary values range from 0 to 15, usually values from 10 to 15 are given the alphabetic
letters from A to F.

However, the Advantage MSP does not utilize standard hex format. Instead, the
Advantage MSP uses what is known as "pseudo-hex." Simply put, instead of using the
letters A, B, C, D, E and F the Advantage MSP uses : ; < = > and ?, respectively. All it
takes to arrive at the new notation for hex values 10 to 15d is to add 30 to the old ASCII
values. In this paper, [pseudo-hex] will appear after the use of a pseudo-hex character.
The changes are traditional hex are summed up below:

Nibble Conversion

Decima

l

0 0 0 0000
1 1 1 0001
2 2 2 0010
3 3 3 0011
4 4 4 0100
5 5 5 0101
6 6 6 0110
7 7 7 0111
8 8 8 1000

9 9 9 1001
10 A : 1010
11 B ; 1011
12 C < 1100
13 D = 1101
14 E > 1110
15 F ? 1111

Computer Control of the Advantage MSP11/MSP22 1

Hex Pseudo-hex Binary

Serial Interface - Data Communications Parameters

The Advantage MSP communicates through its serial port at four different baud rates:
2400, 9600, 19200, and 38400. The factory default setting is 9600 baud. Changing this
rate is accomplished through BiampWin. The Advantage MSP communicates with 8 data
bits, no parity, and 1 stop bit. The Advantage MSP utilizes a subset of the standard 7-bit
ASCII character set.

Control

The Advantage MSP has an RS-232-compatible serial port which allows it to be
controlled by a computer or by a third party system controller (such as those provided by
AMX® or Crestron®). The Advantage MSP offers the following two methods of serial
control:

 Control Button Emulation. This method of control emulates Biamp's standard infrared

remote control transmitter or wall-mount remote control panel. Using this method, single
ASCII characters sent to the device’s serial port cause the device to behave as if a Biamp
remote controller were attached. While Control Button Emulation is simple to perform, it
only provides basic and "one-way" control of the Advantage MSP - it allows the user to
send simple commands to the Advantage MSP, but it does not provide any mechanism
for requesting status information from the Advantage MSP.

 Advanced Control. Advanced control provides a command set which allow "two-way"

control of the Advantage MSP. Using Advanced Control commands, a system may
request status information from the device as well as send commands to the device.
Communication occurs with the Advantage MSP using the Advantage MSP’s serial port.

Control Button Emulation

Control Button Emulation is the simplest form of serial control of the Advantage MSP.
This method of operation allows the user to emulate the operation of a standard Biamp
remote control transmitter.

For each button on a standard Biamp remote control, there is a corresponding ASCII
character. In order to emulate a remote control button, the transmitting system simply
transmits the corresponding ASCII character to the Advantage MSP’s serial port. Each
character received by the Advantage MSP will be echoed back out the serial port.

The standard Biamp remote control devices never exceed a transmission rate of 9
characters per second. If the controlling system wishes to perform Control Button
Emulation at a rate of greater than 20 characters per second (50 msec per character), flow
control should be implemented by waiting for the echo of each character before
transmitting the next character. At slower speeds, flow control should not be necessary.

Computer Control of the Advantage MSP11/MSP22 2

The following table summarizes the ASCII character codes for Control Button Emulation
corresponding to each of the 40 remote control buttons supported by the Advantage MSP.
These button codes are also summarized on the ASCII code chart provided at the end of
this manual. The remote control buttons on the standard Biamp transmitter are numbered
from left to right going from bottom to top with the lower left-hand button being button
number 1.

Using BiampWin, it is possible to program the MSP to respond to these commands.

button 1 'B' (0x42) button 21 'V' (0x56)
button 2 'C' (0x43) button 22 'W' (0x57)
button 3 'D' (0x44) button 23 'X' (0x58)
button 4 'E' (0x45) button 24 'Y' (0x59)
button 5 'F' (0x46) button 25 'Z' (0x5A)
button 6 'G' (0x47) button 26 '[' (0x5B)
button 7 'H' (0x48) button 27 '\' (0x5C)
button 8 'I' (0x49) button 28 ']' (0x5D)
button 9 'J' (0x4A) button 29 '^' (0x5E)
button 10 'K' (0x4B) button 30 '_' (0x5F)
button 11 'L' (0x4C) button 31 '`' (0x60)
button 12 'M' (0x4D) button 32 'b' (0x62)
button 13 'N' (0x4E) button 33 'c' (0x63)
button 14 'O' (0x4F) but t on 34 'd' (0x64)
button 15 'P' (0x50) button 35 'e' (0x65)
button 16 'Q' (0x51) button 36 'f' (0x66)
button 17 'R' (0x52) butt on 37 'g' (0x67)
button 18 'S' (0x53) button 38 'h' (0x68)
button 19 'T' (0x54) button 39 'i' (0x69)
button 20 'U' (0x55) butt on 40 'j' (0x6A)

Simple vs Addressable

The simple method of control button emulation is to send any one of the control button
characters through the serial port to the MSP. The disadvantage to this method is that
every device hooked into the MSP will also hear the command. If any of the other
devices have been programmed with this particular character, they will also respond.

To avoid this problem, the MSP allows addressable control button emulation. By using
the control-button-emulation command, on page 22, control button commands are sent
directly to a specific device.

Computer Control of the Advantage MSP11/MSP22 3

Advanced Control

The Advanced Control command set includes more powerful commands to allow more
flexible control of the Advantage MSP. Unlike Control Button Emulation (which is
basically a one-way control mechanism) advanced control commands allow the MSP to
return information through the serial port,. The following list summarizes the commands
available using Advanced Control, including the ASCII command character associated
with each command:

! execute-command

. set-baud

+ sleep-for-10-seconds

/ get-version

Each Advanced Control command requires at least two parameter bytes (four pseudo-hex
characters) to be sent prior to the command character. Each command will be explained
in detail on the following pages.

(execute selected command)

(set communications speed)

(sleep for 10 seconds, ignoring all communication)

(retrieve the model information and firmware version date)

The MSP differ from some other Advantage products in that it uses one command byte
(the ‘!’ character) to control several different functions. The execute-command
incorporates the utility of several commands by having different parameters control its
function.

Some of the commands cause the Advantage MSP to return information through the
serial port. For each string of information returned to the serial port, the Advantage MSP
terminates the string by transmitting the ASCII carriage return character (0x0D ­represented in this document as  ).

As mentioned earlier, the Advantage MSP will echo all characters it receives, regardless
of whether or not the characters are valid commands or parameters. Characters greater
than 0x7F are reserved and should not be transmitted to the serial port. The Advantage
MSP utilizes a subset of the standard ASCII character set. The following characters have
meaning to the Advantage MSP:

Computer Control of the Advantage MSP11/MSP22 4

character hexadecimal operation

ASCII control characters (0x00 - 0x1F) no operation

SPACE

ASCII

!

thru

0

thru

@
A (0x41) no operation
B

thru

a (0x61) no operation
b

thru

k

thru

{

thru

0x80 thru 0xFF (0x80 - 0xFF) RESERVED

character

/

? (0x30 - 0x3F) pseudo-hex parameters for Advanced Control commands

`

j
z (0x6B - 0x7A) no operation

DEL

(0x20) no operation

(0x21 - 0x2F) Advanced Control commands

(0x40) Control Button Emulation Repeat Code

(0x42 - 0x60) Control Button Emulation commands (buttons 01 - 31)

(0x62 - 0x6A) Control Button Emulation commands (buttons 32 - 40)

(0x7B - 0x7F) no operation

Device Type Bitmask, Device Number Bitmask, and Device Model Bitmask

In a system which has more than one Advantage product connected together, the device
type bitmask and device number bitmask command parameters provide a mechanism to
individually address a particular device (or a combination of devices). Every command in
the advanced control command set requires that a device type bitmask and a device
number bitmask be transmitted as the last two parameter bytes before transmitting the
command character itself. These two bitmask parameters bytes provide a device
addressing capability to specify which of the devices in the system should execute the
command. All devices which are not specifically addressed by these two bitmask values
will ignore the command.

The device type bitmask parameter byte supports up to eight distinct device types - one
bit per device type. The eight device types are:

0x01 [hex] (bit 0) Biamp Advantage DRC 4+4 digital remote control
0x02 [hex] (bit 1) Biamp Advantage EQ28X digitally-controlled graphicEQ
0x04 [hex] (bit 2) Biamp Advantage SPM522D stereo preamp/mixer
0x08 [hex] (bit 3) Biamp Advantage PMX84 programmable matrix switch
0x10 [hex] (bit 4) (reserved for future products)
0x20 [hex] (bit 5) (reserved for future products)
0x40 [hex] (bit 6) (reserved for future products)
0x80 [hex] (bit 7) Advanced Products, such as the Biamp Advantage MSP

The Advantage MSP will only respond to advanced control commands if bit 7 of the
device type bitmask parameter byte is a '1'. A command may be directed to more than
one device type in the system by setting all of the corresponding bits in the device type
bitmask to '1's. If only advanced equipment is being addressed (EQ2828/8 DRI, MSP,
and DDL12) 80 is the only bitmask required to use.

The device number bitmask parameter byte supports up to sixty-four distinct device
numbers:

Computer Control of the Advantage MSP11/MSP22 5

0x00 [hex] Select Device Number 0
0x01 [hex] Select Device Number 1
0x02 [hex] Select Device Number 2
0xFF [hex] Select Device Number 63

A particular Advantage MSP will only respond to advanced control commands if the
device number bitmask parameter byte corresponds to its own device number.

For instance, the bitmask 8007 serves to talk only to advance product (80) number 7 (07).

The device model bitmask is a special number that is reserved exclusively for the
Advantage MSP. Unlike the device type bitmask, which can refer to an entire line of
products, the device model bitmask is reserved just for one device. To retrieve this
setting, the get-version command can be used.

Computer Control of the Advantage MSP11/MSP22 6

! execute-MSP-command

description:

The execute-MSP-command byte causes the MSP to change its operating parameters. To
control each of the varied functions of the MSP, there are several MSP command
numbers that are associated with the execute-MSP-command. In the standard format, the
MSP command number is the 4 bytes preceding the checksum , device type, and device
model bitmasks. The command has control over the gain manager, the input and output
levels, the crossovers, delays, gain matrix, and equalizer.

0x28  0x2A gain manager bypass commands

description:

These commands are used to control the gain manager function, allowing simple ways to
turn on and off individual sections of the GM.

syntax of commands:

The commands in this section share the following parameters:

commands:

0x28
40d

0x29
41d

zz = device number
yy = reserved for checksum (no action parameter)
aa = channel number (01 or 02)
bb = byte containing command status

(bit set = under command control, bit cleared = ignored by command)
bit 0 - reserved
bit 1 - Auto Silence Hold status
bit 2 - Soft Gate status
bit 3 - Limiter status
bit 4- Compressor status
bit 5 - Leveler status
bit 6 - reserved
bit 7 - Gain Manager status

Bypass Any GM Block (channel #, bitfield)
Bypasses multiple sections of the GM with one command
Command Structure: bbaa0028yy80zz!

Enable Any GM Block (channel #, bitfield)
Enables multiple sections of the GM with one command

Command Structure: bbaa0029yy80zz!

Computer Control of the Advantage MSP11/MSP22 7

0x2A
42d

examples:

command: response:

02020028008001! (none)

Here, an MSP (device number 1) is instructed to bypass the Auto Silence Hold (bit 1) of
channel 2.

command: response:
0601002900800:! (none)

This command instructs MSP device number 10d (0: [pseudo-hex]) to activate the soft
gate and the ASH (bits 1 and 2) of channel 1.

command: response:
8002002:008002! (none)

Toggle Bypass of Any GM Block (channel #, bitfield)
Toggles multiple GM section bypass settings with one command
Command Structure: bbaa002:yy80zz!

When executed, this command toggles the gain manager status (bit 7) on MSP device 2,
channel 2. Depending on the status of the GM when called, this will either enable or
disable all sections of the GM.

comments:

The gain manager bit will override the status of the other bits. For instance, if this bit is
used to have the gain manager disabled, all sections of the GM will be disabled also.
Although the GM status overrides the settings of the 5 GM sections, it does not overwrite
the 5 sections.

The MSP11 only responds to commands directed to channel 1.

Computer Control of the Advantage MSP11/MSP22 8