Pfeiffer TC400 User Manual

25
Pfeiffer Vacuum Protocol for "RS485"
8 Pfeiffer Vacuum Protocol for "RS485"
8.1 Telegram frame
The telegram frame of the Pfeiffer Vacuum protocol contains only ASCII code char-
acters [32; 127], the exception being the end character of the message
C
R
. Basically,
a master  (e.g. a PC) sends a telegram, which is answered by a slave  (e.g. elec-
tronic drive unit).
8.2 Telegrams
Data request ?
Control command !
Data response / control command understood 
Error message 
Example 1 Data request
Actual rotation speed (parameter [P:309], device address slave: "123")
Data request: 633 Hz
Actual rotation speed (parameter [P:309], device address slave: "123")
Example 2 Control command
Switch on pumping station (parameter [P:010], device address slave: "042")
a2 a1 a0 * 0 n2 n1 n0 l1 l0 dn ... d0 c2 c1 c0
C
R
a2 - a0 Unit address for slave 
– Individual address of the unit ["001";"255"]
– Group address "9xx" for all identical units (no response)
– global address "000" for all units on the bus (no response)
*Action (see p. 25, chap. 8.2)
n2 - n0 Pfeiffer Vacuum parameter numbers
l1 - l0 Data length dn ... d0
dn - d0 Data in data type concerned (s
ee
p. 26, chap. 8.3)
c
2
- c0 Checksum (sum of ASCII values of cells a2 to d0) modulo 256
C
R
carriage return (ASCII 13)
a2a1a000n2n1n002=?c2c1c0
C
R
a2 a1 a0 1 0 n2 n1 n0 l1 l0 dn ... d0 c2 c1 c0
C
R
a2 a1 a0 1 0 n2 n1 n0 l1 l0 dn ... d0 c2 c1 c0
C
R
a2 a1 a0 1 0 n2 n1 n0 0 6 N O _ D E F c2 c1 c0
C
R
_ RANGE
_ L OGI C
"NO_DEF" The parameter n2 - n0 does not exist
"_RANGE" Data dn - d0 are outside the permitted range
"_LOGIC" Logic access violation
? 1230030902=?112
C
R
ASCII 49505148485148574850616349495013
 1231030906000633037
C
R
ASCII 4950514948514857485448484854515148515513

Pfeiffer TC400 Specifications

General

Brand	Pfeiffer
Model	TC400
Category	Controller
Language	English