Baumer TA134 - Handbuch (Seite 8)

TA134
8 www.baumer.com
Operating manual
Interface description for
TA134 Program 01
1. General information
The serial interface can do the same functions as tachometer display and keypad. The serial interface is for
polling data and programming parameters. Usually, when applying the interface the tachometer is operated by
personal computer, reason why in the following the external upstream device is called PC. However, any other
device with similar specifications can do as well
2. Transmission protocol
Transmission is token by token in ASCII code. Each token is composed of 8 bits. Bit number 8 is the Parity bit, in
case of “no parity” bit number 8 is always zero.
Upon PC request the tachometer transmits a response by serial interface, provided the data transmission was
correct.
The transmission starts by a header info <STX> (start of text) and ends by a footer info <ETX> (end of text).
Further, to <ETX> the tacho adds <CR> (carriage return) what enables reading of a complete data block by one
command (in a high-level language as BASIC).
<STX> is followed by the tacho’s designated identifier what allows addressing a specific tacho in the network.
The identifier is followed by the line (position) to be read out or parameterized. The programming command is
followed by “P” (programming) together with corresponding data (parameters).
The protocol is split into 3 groups as described below:
a) Read memory space (READ instruction):
<STX> identifier line <ETX> [<CR>]
b) Write memory location (WRITE instruction):
<STX> identifier line P data <ETX> [<CR>]
c) Specific commands:
<STX> identifier parameters <ETX> [<CR>]
<STX>
Start of Text (02Hex)
Address 00..99 (device identifier)
Line 01..XX (see operating chart)
P Programming command
Data Parameter data
Parameter Specific commands
<ETX> End of Text (03Hex)
<CR> 0DHex (control token "carriage return")
"CR" is optional and may be omitted but is
always replied by the tacho.
Example:
Standard <STX> identifier line <ETX> (identifier=35; line=02)
Ascii <STX>3502<ETX>
Hex 02H,33H,35H,30H,32H,03H
Important! The space between the individual tokens of a command are for better representation only. Entering
by PC has to be without space. Control tokens (inferior to 20Hex) come in brackets.
In case a wrong protocol is received by PC the tacho returns an error signal, provided it is still in
operating status. Please refer also to chapter “Error signals” on page 5.