VICI Selectors (multiposition) Microelectric - Manual (Page 6)

6
Serial Control of the Actuator
Establishing Serial Communications
Items required:
• Valco cable assembly I-22697 or equivalent
• Terminal emulation or communication software such as QModem, ProComm Plus
™ ,
or HyperTerminal ® (included with Windows ® ), running on a PC-compatible computer
1. Connect the I-22697 cable to the actuator as indicated in Figure 1, and set the serial port at 9600
baud, no parity, 8 data bits, 1 stop bit, no hardware or software handshaking.
2. With the software running, check the bi-directional communication link between the keyboard/
monitor of the computer and the serial port by typing VR<enter>. If the link is functioning and an
actuator ID has not been set, a message similar to the following will appear on your monitor, giving
the program number and date of the actuator firmware.
I-PD-ETX88RXX (XX = revision number)
2 - Aug - 99
If there is no response, it is possible that the ID has already been set. To force a response from
a device with an unknown ID, type *VR<enter>. The asterisk is a substitute ID wild card which will
elicit a response from all devices on line, no matter what their ID is.
Programmer’s note: In order for multiple RS-232 slave devices to be controlled from one serial port,
they must all keep their outputs deactivated until they need to respond. When a device responds, it
asserts its output low for 2 milliseconds before sending the first character to clear the host UART’s
input. Nevertheless, it is possible that the UART will sense a framing error or receive a bogus
character. The programmer should be prepared to handle this possibility in software.
ProComm Plus ™ is a registered trademark of Symantec Corporation
HyperTerminal ® is a registered trademark of Hilgraeve, Inc.
Windows ® is a registered trademark of Microsoft Crop.
Software Input Protocols
The input modes are selected by the serial port command “SD
n”, with n = 0, 1, 2, or 3. Mode
information is stored in non-volatile memory and maintained during power up/down sequences. The
modes are:
SD0 (default) Binary Coded Decimal (BCD) input mode. For the 96 possible input positions, all
8 digital input data lines are required. Refer to the chart on the previous page for the signal line
definitions.
SD1 Disables the digital inputs to prevent user intervention during automated control via the serial
port. It resets to SD0 during the power up sequence.
SD2 Redefines the data input lines so that each input line equates to only one actuator position;
any and all combinations of data input lines are invalid. This mode can support only 8 positions:
1 BCD = position 1; 2 BCD = position 2; 4 BCD = position 3; 8 BCD = position 4; 10 BCD=
position 5; 20 BCD = position 6; 40 BCD = position 7; and 80 BCD = position 8. The offset value
SO is set to 1, and since the number of positions is limited to 8, any user-set NP value greater
than 8 will revert to 8. (See the chart on the next page for more explanation of NP and SO.)
SD3 Redefines the data input lines to a binary input instead of BCD. This reduces the number of
input lines required to select positions above 9. For example, BCD mode inputs for any position
between 10 and 15 requires the use of data input lines 1, 2, 4, 8, and 10 BCD. In the binary
mode, only lines 1, 2, 4, and 8 BCD are required. The position values for the binary mode are
calculated the same way as those for the BCD mode, except that all combinations of the input
lines are valid numerical positions.