BusWorks®
961/962PB Module User’s Manual ProfiBus Differential I/V Input
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:248-624-1541 Fax:248-624-9234 Email:
http://www.acromag.com
19
Bus Idle State:
“1” (a start bit causes line to go to “0”). An idle state of at
least 33 Tbits (sync-time) must be provided between messages.
Note: 1Tbit at 12Mbaud = 1/12000000bit/sec = 83nsec.
Address:
Set via two rotary hexadecimal switches adjacent to the power
terminals, or alternately via the Set Slave Address command. Valid
setting is 0-125 (7 bits). Address 126 (7EH) is the default factory
address and is reserved for commissioning purposes only. Address
127 (7FH) is reserved by the software as a global address for broadcast
messages. If the address switches are set to 126 upon power-up (or
126-254), then the unit will retrieve its address from its internal
EEPROM rather than the switches. The internal EEPROM setting is
modified via the Set Slave Address command. Powering up with
switches set to 255 (FFH) will cause the internal EEPROM setting to
revert back to 126 (7EH), which may be used to recommission the
module. If both the internal EEPROM address and the switches are set
to 126 upon power-up (this is the initial state from the factory), the
module will await the Set Slave Address command before completing
initialization and assuming the data exchange mode.
IMPORTANT (Address Setting):
The internal EEPROM address
setting and external switch setting is 126 from the factory. As such, the
module will await the Set Slave Address command following power-up
and will not proceed to exchange data, unless the external switches are
instead set to an address from 0-125, or the internal setting is changed
to an address from 0-125 via the Set Slave Address command.
Network Capacity:
Multi-drop up to 31 modules, plus a host, without a
repeater. Up to 125 modules plus a host if four repeaters are used (one
for every 31 nodes).
Network Termination:
Use 220Ω “A” to “B”, plus 390Ω “A” to GND, and
390Ω “B” to +5V. Use ±2%, 0.25W resistors.
LED Indicators:
Run (Green) -
Constant ON indicates power is ON and unit is OK.
Flashing ON/OFF indicates unit is performing diagnostics (first few
seconds following power-up), or has failed diagnostics (after a few
seconds).
Bus (Yellow)
–
ON indicates unit has completed its initialization
sequence and is in the data exchange mode on the network.
Switches:
Slave Address:
Two hexadecimal rotary switches are located in the
recessed opening adjacent to the power terminals and represent the
hex MSB & LSB of the 8 bit slave address. See Address above.
I/O values of Acromag 9xxPB modules are represented by the following
simple data types for temperature, percentage, and discrete on/off. Note
that when transferring words, data bytes are transmitted using “Big Endian”
format (MSB first, LSB second).
Communication
Interface
Controls & Indicators
Data Types
