因为正本系统中多块SDC控制表面出现缺点，在维修中选用plc对原系统做更换改造。正本控制系统结束对洁净房室内温度、湿度、室内外压差进行查看并控制。室内空气恳求为100级。空气通过过滤后成为洁净空气，满足出产线对空气洁净度、温湿度的恳求。
一． 系统工作原理
新风机鼓入的新风经加热交流器、制冷交流器、加湿器进入房间。房间内有温度、湿度、差压查看器测的信号反响给控制器。由反响信号通过数字控制仪来控制加热、制冷交流器控制室内温度。当湿度低时，由加湿器输出蒸汽；湿度高时，制冷交流器要降温以使空气温度降低，到达除湿目的。正本的湿度、温度信号还要通过高选处理。当温度信号高时，以温度控制优先；当湿度信号高时，以湿度控制优先。正本表面调试比照冗繁，调试不简略满足恳求。加热、制冷、加湿器的控制信号是4-20mA信号。压力系统正本是由变频器控制。本次改造并没有触及。
二． 改造计划
温度、湿度信号是变送器送出的DC 4-20mA 的信号。输入的信号通过比照判别，当输入的温度信号小于12mA时，要实行加热逻辑，当大于12mA时，要实行制冷逻辑。当输入的湿度信号小于12mA时，要实行加湿逻辑，当大于12mA时，要实行除湿逻辑。而制冷和除湿信号中要选大的来控制制冷交流器。因为PLC有极好的逻辑判别才华及数据处理才华，改造中选用了台达DVPSS系列PLC。SS系列是模块式构造，可以根据恳求装备不一样的仿照模块和数字量模块。因为是改造，我们运用的数字量很少，仅用做缺点报警。DVP14SS CPU有8点输入/6点输出。根据我们需求又装备了DVP04AD-S仿照输入模块和DVP04DA-S仿照输出模块。

TURCK BL20-16DI-24VDC-P 1
ULTRA SLIMPAK G428-0001 1
UNIOP ELT-VGA-0045 1
VALMET CPR1 A413280 1
VALMET A413045 3
VALMET 421907-1B 1
VALMET A413052 1
VALMET 421907-1B 2
VEXTA A3897-9412 1
VEXTA PH266-01GK-C5 1
VISHAY 120NQ045R 4
VMIC VMIVME Model 2533 Assy No 332-002533-010E 1
VMIC ZT5524A1A 1
VWR SCIENTIFIC MODEL 3000 1
WEIDMULLER 836598 1
WEIDMULLER 844495000 1
WEIDMULLER 8533640000 1
WEIDMULLER 844725 2
WEIDMULLER 8540180000 1
WEIDMULLER 8560740000 1
WEIDMULLER 860736000 1
WEIDMULLER 8690880000 1
WEIDMULLER V23057-B3028-A101 1
WEIDMULLER 0302860000 40
WEIDMULLER 7940005785 1
WEIDMULLER 7901620000 1
WEISTINGHOUSE 1C31238H01 1
WEISTINGHOUSE 1C31238H01 1
WEISTINGHOUSE 1C31234G01 2
WEISTINGHOUSE 1C31227GO1 2
WEISTINGHOUSE 1C31238H01 1
WEISTINGHOUSE 1C31234G01 3
WEISTINGHOUSE 1C31227G01 2
WEISTINGHOUSE 1C31224GO1 1
WEISTINGHOUSE 1C31224G01 3
WEISTINGHOUSE 1C31233G04 1
WEISTINGHOUSE 5X00167G01 2
WEISTINGHOUSE 1C31127G01 2
WEISTINGHOUSE 1C31125G02 2
WEISTINGHOUSE 1C31116G04 2
WEISTINGHOUSE 1B30023H01 2
WEISTINGHOUSE 1C31132G01 1
WEISTINGHOUSE 5X00321G01 2
WESTINGHOUSE 3A99158G01 19
WESTINGHOUSE ST24B3 12
WESTINGHOUSE AID-1(西屋键盘) 5
WESTINGHOUSE 5A26391H24 9
WESTINGHOUSE 3A99132G01 2
WESTINGHOUSE 3A99132G02 8
WESTINGHOUSE 1C31234G01 5
WESTINGHOUSE 1C31234G01 3
WESTINGHOUSE 1C31234G01 2
WESTINGHOUSE 4D33942G01 6
WESTINGHOUSE 3A99200G01 6
WESTINGHOUSE 1C31234G01 55
WESTINGHOUSE 1X00024H01 1
WESTINGHOUSE 5X00119G01 1
WESTINGHOUSE 1X00024H01 3
WESTINGHOUSE 1X00416H01 1
WESTINGHOUSE ZX345Q 8
WESTINGHOUSE 5X00241G01 2
WESTINGHOUSE 5X00226G02 2
WESTINGHOUSE 5X00119G01 1
WESTINGHOUSE 1C31238H01 2
WESTINGHOUSE 1C31238H01 4
WESTINGHOUSE 1C31238H01 3
WESTINGHOUSE 1C31238H01 2
WESTINGHOUSE 5X00105G14 1
WESTINGHOUSE 5X00105G01 2
WESTINGHOUSE 5X00059G01 2
WESTINGHOUSE 5X00058G01 2
WESTINGHOUSE 1C31234G01 4
WESTINGHOUSE 1C31224G01 3
WESTINGHOUSE 1C31161G02 45
WESTINGHOUSE 1C31150G01 4
WESTINGHOUSE 1C31147G01 4
WESTINGHOUSE 1C31197G01 2
WESTINGHOUSE 1C31203G01 1
WESTINGHOUSE 1C31204G01 1
WESTINGHOUSE 1C31164G02 59
WESTINGHOUSE 1C31132G01 2
WESTINGHOUSE 1C31224G01 13
WESTINGHOUSE 1C31224G01 2
WESTINGHOUSE 1C31224G01 2
WESTINGHOUSE 1C31224G01 4
WESTINGHOUSE 1C31132G01 1
WESTINGHOUSE 1C31132G01 9
WESTINGHOUSE 1C31189G01 1
WESTINGHOUSE 1C31194G01 2
WESTINGHOUSE 1C31194G01 1
WESTINGHOUSE 1C31192G01 2
WESTINGHOUSE 1C31192G01 1
WESTINGHOUSE 1C31189G01 2
WESTINGHOUSE 1C31166G01 1
WESTINGHOUSE 1C31179G02 1
WESTINGHOUSE 1C31194G02 3
WESTINGHOUSE 1C31169G02 1
WESTINGHOUSE 1C31194G03 2
WESTINGHOUSE 1C31197G01 2
WESTINGHOUSE 1C31166G01 1
WESTINGHOUSE 1C31113G02 31
WESTINGHOUSE 1C31125G02 1
WESTINGHOUSE 1C31227G01 2
WESTINGHOUSE 1C31227G01 2
WESTINGHOUSE 1B30035H01 3
WESTINGHOUSE 1C31227G01 4
WESTINGHOUSE 1C31129G03 2
WESTINGHOUSE 1C31227G01 1
WESTINGHOUSE 1C31227G02 2
WESTINGHOUSE 1C31125G02 42
WESTINGHOUSE 1C31122G01 1
WESTINGHOUSE 1C31122G01 30
WESTINGHOUSE 1C31116G04 17
WESTINGHOUSE 1B30023H01 4
WESTINGHOUSE 1B30035H01 72
WESTINGHOUSE 1C31129G03 2
WESTINGHOUSE 1C31227G01 52
WESTINGHOUSE 1B30035H01 2
WESTINGHOUSE 1C31129G03 12
WESTINGHOUSE 1C31132G01 1
WESTINGHOUSE 1B30035H01 2
WESTOVER SCIENTIFIC FM-C200 1
WOHNER 31110 1
WOODHEAD 5136-PFB-VME 1
WOODWARD 5464-414 1
WOODWARD 9907-175 1
WOODWARD 9907-164 1
WOODWARD 9907-164 1
WOODWARD 9907-028 1
WOODWARD 9907-252 1
WOODWARD 2301A /9905-020 1
WOODWARD 9907-162 1
XANTREX XFR40-30 1
XANTREX XFR40-70 1
XANTREX XFR 20-130 1
XYCOM XVME-653 0
XYCOM XVME-530 1
XYCOM XVME-976 1
XYCOM Proto XVME-085 1
YAMAHA RCX40 1
YAMATAKE HD-CAOBS00 3
YASKAWA JGSM-06 1
YASKAWA CACR-HR10BB 1
YASKAWA AI-01 1
YASKAWA JRMSP-P8101 1
YASKAWA JRMSI-B1026 1
YASKAWA CIMR-M5D2018 1
YASKAWA JEPMC-PC040 1
YASKAWA JEPMC-MC001 1
YASKAWA JEPMC-CP210T2V 1
YASKAWA JANCD-XCP01-1 1
YASKAWA JANCD-PC51 1
YASKAWA JANCD-MSV01B 1
YASKAWA JANCD-MIF01 1
YASKAWA JANCD-MCP02B-1 1
YASKAWA PS-02 1
YASKAWA LASC-100SUB 1
YASKAWA CP-9200SH/SVA 1
YASKAWA NPSO-0503L 1
YASKAWA MB-01 1
YASKAWA LIO-01 2
YASKAWA LI0-01 1
YASKAWA LASC-100W8 1
YASKAWA PS-01 2
YASKAWA JZNC-XPP02B 1
YASKAWA JZNC-XIU01B 1
YASKAWA JZNC-MRK12-1E 1
YASKAWA JUSP-WS15AB 1
YASKAWA DI-01 7
YASKAWA JUSP-NS300 1
YASKAWA CP-9200SH/CPU 4
YASKAWA SGMAH-02AAA21 2
Yaskawa JZNC-XPP02B 1
YASKAWA JACP-317900 1
YASKAWA JANCD-JSP04-1 1
YASKAWA JAMSC-B1050 3
YASKAWA JAMSC-B1063 1
YASKAWA JAMSC-B1070 1
YASKAWA SJDE-04ANA-OY 1
YASKAWA JAMSC-B1071 1
YASKAWA JANCD-CP50B 1
YASKAWA JACP-317900 1
YASKAWA SGDS-08A01A 1
YASKAWA JAMSC-C8120 1
YASKAWA JAMSI-B1031 1
YASKAWA CPS-18F8 1
YASKAWA JAMSC-C8160 1
YASKAWA CP-9200SH/CPU 2
YASKAWA CP-9200SH/SVA 1
YASKAWA CP-9200SH/SVA 1
YASKAWA CP-9200SH/SVA 7