Trouble using MCS mode with mcaR7-6 and Canberra DSA-2000

[hank <hank@wv7u.com>]

Hello, I'm an individual user of EPICS, initially mainly to make use of 
the MCA components and AIM support with a Canberra DSA-2000, but I'm 
also having success using it for control of other instruments and data 
acquisition around the lab.
I'm trying to use the DSA-2000 in MCS mode, without any luck so far, but 
I'll admit I'm unclear on some of the terminology in the AIM/ICB setup 
instructions, MCA and DSP settings, and even what to expect in general. 
MCA/PHA mode seems to work fine, so I think most of my EPICS MCA 
installation is working correctly.
From what I've read about the MCS function in the DSA-2000 manual, I 
thought I should be able to set a ROI, Mode=MCS, dwell time, and 
internal channel advance, and have it work in simple MCS mode. I see 
most of these controls in the MEDM MCA Setup window, although I'm not 
sure where MCS-related ROI(s) would be specified, or if that is 
possible. The AIM/ICB setup instructions give an example for collecting 
"20 spectra". Does that mean 20 ROIs for which MCS data is collected?
The behavior I'm seeing is that when I set the mode to MCS in the MCA 
Setup MEDM window, nothing seems to change from the normal MCA/PHA 
display in the mcaTest:aim_adc1 MEDM window. I expected to see the graph 
change to one with the channels representing the MCS time bins. Also 
when I try to set the dwell time to something other than zero, it 
immediately reverts back to zero at the next update.
Some system info and modules installed for using MCA:
ARCH: Debian, linux-x86_64
mcaR7-6
asyn4-24
autosave-5-4-2
base-3.14.12.4
busy-1-6
calc-3-4-1
medm3_1_9 and caqtdm-4.0.2
seq-2.1.10
sscan-2-10
std-3-2
also using StreamDevice and StripTool for other apps

I'm not using a multiplexer, and I want to count across 1024 time bins 
(each of (dwell time) per bin), so I start up with the commands:
------------------------------------------------
< envPaths
epicsEnvSet(STARTUP,$(TOP)/iocBoot/$(IOC))

dbLoadDatabase("../../dbd/mcaCanberra.dbd",0,0)
mcaCanberra_registerRecordDeviceDriver(pdbbase)

# AIMConfig(portName, ethernet_address, portNumber(1 or 2), maxChans,
#           maxSignals, maxSequences, ethernetDevice)
AIMConfig("AIM1/1", 0x801c, 1, 1024, 1, 1, "eth0")

dbLoadRecords("/home/hank/epics/mcaR7-6/mcaApp/Db/mca.db", 
"P=mcaTest:,M=aim_adc1,DTYP=asynMCA,INP=@asyn(AIM1/1 0),NCHAN=1024")
icbConfig("icbDsp1", 0x801c, 0, 4)

dbLoadRecords("/home/hank/epics/mcaR7-6/mcaApp/Db/icbDsp.db", 
"P=mcaTest:,DSP=dsp1,PORT=icbDsp1")
DSA2000Config("DSA2000",0x801c)
dbLoadRecords("/home/hank/epics/mcaR7-6/mcaApp/Db/DSA2000_HVPS.db", 
"P=mcaTest:,HVPS=hvps1:,PORT=DSA2000,LIMIT=5000")
< save_restore.cmd

set_pass0_restoreFile("DSA2000_settings.sav")
set_pass1_restoreFile("DSA2000_settings.sav")

iocInit()

# save settings every thirty seconds
create_monitor_set("DSA2000_settings.req",30,"P=mcaTest:"
------------------------------------------------

This results in the behavior I described above.

Results of AIM and ICB showModules:

epics> mcaAIMShowModules
Module     Type  HW rev.  FW rev.  Owner name      Owner ID Status      
Memory size Free address
NI00801c    1       2        7       lab01     08:00:27:AF:23:44 
Reachable     262140      00001000

epics> icbShowModules
NI801C:0   9  O5�   12982655

Hex translation:
00000000  4e 49 38 30 31 43 3a 30  20 20 20 39 20 20 10 4f |NI801C:0   
9  .O|
00000010  35 ef bf bd 11 7f 20 20  20 31 32 39 38 32 36 35 |5.....   
1298265|
00000020  35 0a                                             |5.|

Hopefully someone will be able to tell me what I'm doing wrong. Thanks 
to the EPICS contributors for the excellent software, and thanks in 
advance for any help you can provide.
Hank Ball