Numa-Logic PC1100 / 1200 / 1250 Family

The Numa-Logic PC1100 was a small (originally only 128 digital and 16 analog I/O supported) PLC developed by Westinghouse in the mid 1980's. It was designed to use the same programming methods as the earlier PC900 and PC700 processors and, in fact, the programs were portable between all three classes of machine as long as the program did not exceed a limit imposed by that processor. An example of a limit would be attempting to load a program that used more memory, I/O or functions than were physically available in the smaller machine. This PC1100 processor could be programmed in a variety of ways including using a dedicated CRT programming console, a small "Mini-Loader" or an IBM-compatible MS-DOS personal computer.

The CRT (NLPL-780) would support printing to an RS-232 serial printer and would support connection to an NLT-783 STR-LINK cassette tape storage system. The Mini-Loader (NLPL-789) offered neither option, but one version (NLPL-789-10-2) did include 1/8" (mini) audio jacks that could be connected to a conventional audio tape recorder to both store and retrieve programs. Note that the audio recording made with the Mini-Loader could not be used by the STR-LINK or vice versa.

Westinghouse offered the Advanced Program Loader (APL) in the form of packaged solutions made up of either Compaq or IBM PCs, a suitable RS-232 cable (NLC-6PL: 25-pin or NLC-5PL: 9-pin version) as well as MS-DOS compatible software.

Several versions of software were available including NLSW-783, NLSW-783U (included off-line utilities) and NLSW-784 (included ability to document program). The somewhat ground-breaking choice of using a personal computer as a program loader allowed several advanced functionality features to be added over time since the underlying loader was, in fact, a computer. This allowed third party applications to be developed independently from the Westinghouse Numa-Logic factory.

For example, an add-on package called "Westinghouse Help Outline" (WHO) or more typically "Online Utilities" was made available as a terminate and stay resident (TSR) program. This TSR program would link with the NLSW-78x program to provide additional functionality. For example, WHO included such additional functionality as a telephone dialer (allow program loader access to a remote PLC connected to an auto-answer modem), advanced PID loop tuning, remote keyswitch control, remote networking using either the PC1100 LAN or via Westnet II Data Highway as well as on-line cross-referencing of used special function and available coils.

All Westinghouse program loaders were programmed in 8088 assembly language and were surprisingly responsive (0.2 sec screen refresh), even using the standard 9600 bps link between the IBM PC RS-232 port and the RS-232 port on the PC1100/1200/1250 and recognizing that the underlying computer was typically running on a 4.77 MHz 16-bit internal / 8-bit external CPU. Later Westinghouse offered Toshiba "clam-shell" computers including the T5100 (shown in APL photo above) and the T3200SXC. Both of these computers used the faster 32-bit 80386 (T3200SXC used the 32-bit internal / 16-bit external 80386SX) processors. The latter was the first clam-shell computer with a color screen (VGA 640x480).

Later versions of PLCs using the same form factor and I/O as the PC1100 included the more capable and powerful PC1200 and PC1250 processors. In particular, the PC1250 expanded the capabilities (512 digital plus 256 analog I/O) of the family well into the mid-range of PLCs for that time.

The PC1100 used 3 standard AA batteries to maintain battery backed up RAM. The advertised life was 3 months with power off and 1 year with power on. The PC1200/1250 used one 3.5 V AA lithium battery. The lithium battery offered substantially longer battery life at 1 year with power off and 5 years with power on.

Refer to the PC1100/1200/1250 Systems Manual1 below for more details on this processor family. Note that the Appendix D - New Special Functions only applies to certain PC1200/1250 systems manufactured after 1990. Units built prior to that date did not include these functions. Also, even if some special functions were available, not all functions were built into each processor. Westinghouse sold different versions of each PLC, each having differing amounts of memory and available special functions.

PC1100/1200/1250 Systems Manual1

Table of Contents
Section 1 - Introduction
Section 2 - System Overview
Section 3 - Installation and Start-Up
Section 4 - Programming Approach
Section 5 - Special Functions (5-1 to 5-77) (5-78 to 5-163) (5-164 to 5-294)
Section 6 - Troubleshooting
Appendix A - Glossary
Appendix B - Controller Specifications
Appendix C - I/O Module Addressing Details
Appendix D - New Special Functions

To keep the file download sizes below 4 MB each, Section 5 - Special Functions has been divided into three parts. Refer to the list below of special functions to locate the page number within either Section 5 or Appendix D where that particular special function is described in more detail. Note that the page numbering for Appendix D also started with the number 5, so refer to the column "Section" to know whether that particular special function is described in Section 5 or in Appendix D.

Special Function Name Section Pages
AB ASCII to Binary Appendix D 5-3 to 5-8
AD Add Section 5 5-5 to 5-9
AM AND Matrix Section 5 5-10 to 5-14
AR ASCII Receive (PC1100 Version) Section 5 5-15 to 5-19
AR ASCII Receive (PC1200 Version)  Section 5 5-20 to 5-24
AS Ascending Sort Section 5 5-25 to 5-29
AT ASCII Transmit Section 5 5-30 to 5-46
BC Bit Clear Section 5 5-57 to 5-59
BD Binary to Binary Code Decimal (BCD) Section 5 5-47 to 5-49
BF Bit Follow Section 5 5-50 to 5-51
BM (Indirect) Block Move Appendix D 5-9 to 5-16
BO Bit Operate Section 5 5-52 to 5-56
BS Bit Set Section 5 5-57 to 5-59
BT Block (Table) Transfer Section 5 5-60 to 5-63
BU Byte Unpack Appendix D 5-17 to 5-20
BZ Bit Zero Appendix D 5-21 to 5-24
CB Compress Bit Appendix D 5-25 to 5-28
CG Continuous Group Select Section 5 5-64 to 5-65
CM Complement Matrix Section 5 5-66 to 5-70
CP Configure (Serial) Port Section 5 5-71 to 5-77
CR Control Relay Section 5 5-78 to 5-80
CT Close Table Section 5 5-207 to 5-211
CX Checksum Appendix D 5-29 to 5-36
DB Binary Coded Decimal (BCD) to Binary Section 5 5-47 to 5-49
DC Down Counter Section 5 5-278 to 5-281
DV Divide Section 5 5-81 to 5-85
EQ Equal to (comparison) Section 5 5-86 to 5-89
ER Extend Register Appendix D 5-37 to 5-40
FI First In (stack push) Section 5 5-90 to 5-95
FO First Out (stack pull) Section 5 5-90 to 5-95
GE Greater Than or Equal to (comparison) Section 5 5-86 to 5-89
IM Indirect Move Section 5 5-102 to 5-106
LC Loop Controller (PID) Section 5 5-107 to 5-163
LO Last Out (roll off send of stack) Section 5 5-96 to 5-101
LR Latch Read Section 5 5-164 to 5-168
LS Lock Scan Section 5 5-169 to 5-174
LT Literal Special Function Section 5 5-175 to 5-178
LX Limit Check Appendix D 5-41 to 5-44
MB Move Byte Section 5 5-179 to 5-183
MP Multiply Section 5 5-184 to 5-187
MR Master Control Relay Section 5 5-188 to 5-190
MV Move (single 16-bit word) Section 5 5-191 to 5-193
NL N-bit Serial Shift Register Left Section 5 5-194 to 5-200
NR N-bit Serial Shift Register Right Section 5 5-194 to 5-200
OM OR Matrix Section 5 5-201 to 5-206
OT Open Table Section 5 5-207 to 5-211
PB Pack Byte Appendix D 5-45 to 5-48
PT Port Transmit Section 5 5-212 to 5-231
RP Restore Program Counter Section 5 5-232 to 5-237
RW Reset Watchdog Timer Section 5 5-238 to 5-242
SB Subtract Section 5 5-5 to 5-9
SC Scale Appendix D 5-49 to 5-53
SK Skip Section 5 5-243 to 5-245
SM Search Matrix Section 5 5-246 to 5-250
SP Save Program Counter Section 5 5-251 to 5-252
SQ Square Root Section 5 5-253 to 5-258
TL Table Look Up Section 5 5-259 to 5-262
TO Table Look Up Ordered Section 5 5-259 to 5-262
TR Table to Register Section 5 5-263 to 5-268
TS Timer, Seconds Section 5 5-269 to 5-274
TT Timer, Tenths of Second Section 5 5-269 to 5-274
UA Unit Address Section 5 5-275 to 5-277
UC Up Counter Section 5 5-278 to 5-281
UI Update Immediate Section 5 5-282 to 5-284
US Update Select Section 5 5-285 to 5-287
XM Exclusive OR (XOR) Matrix Section 5 5-288 to 5-292
Battery Status Coil Section 5 5-293

1 A subset of these functions were available on the older PC700 and PC900 programmable controllers.

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